1 /*-------------------------------------------------------------------------
2 *
3 * tablecmds.c
4 * Commands for creating and altering table structures and settings
5 *
6 * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/commands/tablecmds.c
12 *
13 *-------------------------------------------------------------------------
14 */
15 #include "postgres.h"
16
17 #include "access/genam.h"
18 #include "access/heapam.h"
19 #include "access/multixact.h"
20 #include "access/reloptions.h"
21 #include "access/relscan.h"
22 #include "access/sysattr.h"
23 #include "access/tupconvert.h"
24 #include "access/xact.h"
25 #include "access/xlog.h"
26 #include "catalog/catalog.h"
27 #include "catalog/dependency.h"
28 #include "catalog/heap.h"
29 #include "catalog/index.h"
30 #include "catalog/indexing.h"
31 #include "catalog/namespace.h"
32 #include "catalog/objectaccess.h"
33 #include "catalog/pg_am.h"
34 #include "catalog/pg_collation.h"
35 #include "catalog/pg_constraint.h"
36 #include "catalog/pg_constraint_fn.h"
37 #include "catalog/pg_depend.h"
38 #include "catalog/pg_foreign_table.h"
39 #include "catalog/pg_inherits.h"
40 #include "catalog/pg_inherits_fn.h"
41 #include "catalog/pg_namespace.h"
42 #include "catalog/pg_opclass.h"
43 #include "catalog/pg_tablespace.h"
44 #include "catalog/pg_trigger.h"
45 #include "catalog/pg_type.h"
46 #include "catalog/pg_type_fn.h"
47 #include "catalog/storage.h"
48 #include "catalog/storage_xlog.h"
49 #include "catalog/toasting.h"
50 #include "commands/cluster.h"
51 #include "commands/comment.h"
52 #include "commands/defrem.h"
53 #include "commands/event_trigger.h"
54 #include "commands/policy.h"
55 #include "commands/sequence.h"
56 #include "commands/tablecmds.h"
57 #include "commands/tablespace.h"
58 #include "commands/trigger.h"
59 #include "commands/typecmds.h"
60 #include "commands/user.h"
61 #include "executor/executor.h"
62 #include "foreign/foreign.h"
63 #include "miscadmin.h"
64 #include "nodes/makefuncs.h"
65 #include "nodes/nodeFuncs.h"
66 #include "nodes/parsenodes.h"
67 #include "optimizer/clauses.h"
68 #include "optimizer/planner.h"
69 #include "parser/parse_clause.h"
70 #include "parser/parse_coerce.h"
71 #include "parser/parse_collate.h"
72 #include "parser/parse_expr.h"
73 #include "parser/parse_oper.h"
74 #include "parser/parse_relation.h"
75 #include "parser/parse_type.h"
76 #include "parser/parse_utilcmd.h"
77 #include "parser/parser.h"
78 #include "pgstat.h"
79 #include "rewrite/rewriteDefine.h"
80 #include "rewrite/rewriteHandler.h"
81 #include "rewrite/rewriteManip.h"
82 #include "storage/bufmgr.h"
83 #include "storage/lmgr.h"
84 #include "storage/lock.h"
85 #include "storage/predicate.h"
86 #include "storage/smgr.h"
87 #include "utils/acl.h"
88 #include "utils/builtins.h"
89 #include "utils/fmgroids.h"
90 #include "utils/inval.h"
91 #include "utils/lsyscache.h"
92 #include "utils/memutils.h"
93 #include "utils/relcache.h"
94 #include "utils/ruleutils.h"
95 #include "utils/snapmgr.h"
96 #include "utils/syscache.h"
97 #include "utils/tqual.h"
98 #include "utils/typcache.h"
99
100
101 /*
102 * ON COMMIT action list
103 */
104 typedef struct OnCommitItem
105 {
106 Oid relid; /* relid of relation */
107 OnCommitAction oncommit; /* what to do at end of xact */
108
109 /*
110 * If this entry was created during the current transaction,
111 * creating_subid is the ID of the creating subxact; if created in a prior
112 * transaction, creating_subid is zero. If deleted during the current
113 * transaction, deleting_subid is the ID of the deleting subxact; if no
114 * deletion request is pending, deleting_subid is zero.
115 */
116 SubTransactionId creating_subid;
117 SubTransactionId deleting_subid;
118 } OnCommitItem;
119
120 static List *on_commits = NIL;
121
122
123 /*
124 * State information for ALTER TABLE
125 *
126 * The pending-work queue for an ALTER TABLE is a List of AlteredTableInfo
127 * structs, one for each table modified by the operation (the named table
128 * plus any child tables that are affected). We save lists of subcommands
129 * to apply to this table (possibly modified by parse transformation steps);
130 * these lists will be executed in Phase 2. If a Phase 3 step is needed,
131 * necessary information is stored in the constraints and newvals lists.
132 *
133 * Phase 2 is divided into multiple passes; subcommands are executed in
134 * a pass determined by subcommand type.
135 */
136
137 #define AT_PASS_UNSET -1 /* UNSET will cause ERROR */
138 #define AT_PASS_DROP 0 /* DROP (all flavors) */
139 #define AT_PASS_ALTER_TYPE 1 /* ALTER COLUMN TYPE */
140 #define AT_PASS_OLD_INDEX 2 /* re-add existing indexes */
141 #define AT_PASS_OLD_CONSTR 3 /* re-add existing constraints */
142 #define AT_PASS_COL_ATTRS 4 /* set other column attributes */
143 /* We could support a RENAME COLUMN pass here, but not currently used */
144 #define AT_PASS_ADD_COL 5 /* ADD COLUMN */
145 #define AT_PASS_ADD_INDEX 6 /* ADD indexes */
146 #define AT_PASS_ADD_CONSTR 7 /* ADD constraints, defaults */
147 #define AT_PASS_MISC 8 /* other stuff */
148 #define AT_NUM_PASSES 9
149
150 typedef struct AlteredTableInfo
151 {
152 /* Information saved before any work commences: */
153 Oid relid; /* Relation to work on */
154 char relkind; /* Its relkind */
155 TupleDesc oldDesc; /* Pre-modification tuple descriptor */
156 /* Information saved by Phase 1 for Phase 2: */
157 List *subcmds[AT_NUM_PASSES]; /* Lists of AlterTableCmd */
158 /* Information saved by Phases 1/2 for Phase 3: */
159 List *constraints; /* List of NewConstraint */
160 List *newvals; /* List of NewColumnValue */
161 bool new_notnull; /* T if we added new NOT NULL constraints */
162 int rewrite; /* Reason for forced rewrite, if any */
163 Oid newTableSpace; /* new tablespace; 0 means no change */
164 bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */
165 char newrelpersistence; /* if above is true */
166 /* Objects to rebuild after completing ALTER TYPE operations */
167 List *changedConstraintOids; /* OIDs of constraints to rebuild */
168 List *changedConstraintDefs; /* string definitions of same */
169 List *changedIndexOids; /* OIDs of indexes to rebuild */
170 List *changedIndexDefs; /* string definitions of same */
171 char *replicaIdentityIndex; /* index to reset as REPLICA IDENTITY */
172 char *clusterOnIndex; /* index to use for CLUSTER */
173 } AlteredTableInfo;
174
175 /* Struct describing one new constraint to check in Phase 3 scan */
176 /* Note: new NOT NULL constraints are handled elsewhere */
177 typedef struct NewConstraint
178 {
179 char *name; /* Constraint name, or NULL if none */
180 ConstrType contype; /* CHECK or FOREIGN */
181 Oid refrelid; /* PK rel, if FOREIGN */
182 Oid refindid; /* OID of PK's index, if FOREIGN */
183 Oid conid; /* OID of pg_constraint entry, if FOREIGN */
184 Node *qual; /* Check expr or CONSTR_FOREIGN Constraint */
185 List *qualstate; /* Execution state for CHECK */
186 } NewConstraint;
187
188 /*
189 * Struct describing one new column value that needs to be computed during
190 * Phase 3 copy (this could be either a new column with a non-null default, or
191 * a column that we're changing the type of). Columns without such an entry
192 * are just copied from the old table during ATRewriteTable. Note that the
193 * expr is an expression over *old* table values.
194 */
195 typedef struct NewColumnValue
196 {
197 AttrNumber attnum; /* which column */
198 Expr *expr; /* expression to compute */
199 ExprState *exprstate; /* execution state */
200 } NewColumnValue;
201
202 /*
203 * Error-reporting support for RemoveRelations
204 */
205 struct dropmsgstrings
206 {
207 char kind;
208 int nonexistent_code;
209 const char *nonexistent_msg;
210 const char *skipping_msg;
211 const char *nota_msg;
212 const char *drophint_msg;
213 };
214
215 static const struct dropmsgstrings dropmsgstringarray[] = {
216 {RELKIND_RELATION,
217 ERRCODE_UNDEFINED_TABLE,
218 gettext_noop("table \"%s\" does not exist"),
219 gettext_noop("table \"%s\" does not exist, skipping"),
220 gettext_noop("\"%s\" is not a table"),
221 gettext_noop("Use DROP TABLE to remove a table.")},
222 {RELKIND_SEQUENCE,
223 ERRCODE_UNDEFINED_TABLE,
224 gettext_noop("sequence \"%s\" does not exist"),
225 gettext_noop("sequence \"%s\" does not exist, skipping"),
226 gettext_noop("\"%s\" is not a sequence"),
227 gettext_noop("Use DROP SEQUENCE to remove a sequence.")},
228 {RELKIND_VIEW,
229 ERRCODE_UNDEFINED_TABLE,
230 gettext_noop("view \"%s\" does not exist"),
231 gettext_noop("view \"%s\" does not exist, skipping"),
232 gettext_noop("\"%s\" is not a view"),
233 gettext_noop("Use DROP VIEW to remove a view.")},
234 {RELKIND_MATVIEW,
235 ERRCODE_UNDEFINED_TABLE,
236 gettext_noop("materialized view \"%s\" does not exist"),
237 gettext_noop("materialized view \"%s\" does not exist, skipping"),
238 gettext_noop("\"%s\" is not a materialized view"),
239 gettext_noop("Use DROP MATERIALIZED VIEW to remove a materialized view.")},
240 {RELKIND_INDEX,
241 ERRCODE_UNDEFINED_OBJECT,
242 gettext_noop("index \"%s\" does not exist"),
243 gettext_noop("index \"%s\" does not exist, skipping"),
244 gettext_noop("\"%s\" is not an index"),
245 gettext_noop("Use DROP INDEX to remove an index.")},
246 {RELKIND_COMPOSITE_TYPE,
247 ERRCODE_UNDEFINED_OBJECT,
248 gettext_noop("type \"%s\" does not exist"),
249 gettext_noop("type \"%s\" does not exist, skipping"),
250 gettext_noop("\"%s\" is not a type"),
251 gettext_noop("Use DROP TYPE to remove a type.")},
252 {RELKIND_FOREIGN_TABLE,
253 ERRCODE_UNDEFINED_OBJECT,
254 gettext_noop("foreign table \"%s\" does not exist"),
255 gettext_noop("foreign table \"%s\" does not exist, skipping"),
256 gettext_noop("\"%s\" is not a foreign table"),
257 gettext_noop("Use DROP FOREIGN TABLE to remove a foreign table.")},
258 {'\0', 0, NULL, NULL, NULL, NULL}
259 };
260
261 struct DropRelationCallbackState
262 {
263 char relkind;
264 Oid heapOid;
265 bool concurrent;
266 };
267
268 /* Alter table target-type flags for ATSimplePermissions */
269 #define ATT_TABLE 0x0001
270 #define ATT_VIEW 0x0002
271 #define ATT_MATVIEW 0x0004
272 #define ATT_INDEX 0x0008
273 #define ATT_COMPOSITE_TYPE 0x0010
274 #define ATT_FOREIGN_TABLE 0x0020
275
276 static void truncate_check_rel(Relation rel);
277 static List *MergeAttributes(List *schema, List *supers, char relpersistence,
278 List **supOids, List **supconstr, int *supOidCount);
279 static bool MergeCheckConstraint(List *constraints, char *name, Node *expr);
280 static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel);
281 static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel);
282 static void StoreCatalogInheritance(Oid relationId, List *supers);
283 static void StoreCatalogInheritance1(Oid relationId, Oid parentOid,
284 int32 seqNumber, Relation inhRelation);
285 static int findAttrByName(const char *attributeName, List *schema);
286 static void AlterIndexNamespaces(Relation classRel, Relation rel,
287 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved);
288 static void AlterSeqNamespaces(Relation classRel, Relation rel,
289 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
290 LOCKMODE lockmode);
291 static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
292 bool recurse, bool recursing, LOCKMODE lockmode);
293 static ObjectAddress ATExecValidateConstraint(List **wqueue, Relation rel,
294 char *constrName, bool recurse, bool recursing,
295 LOCKMODE lockmode);
296 static int transformColumnNameList(Oid relId, List *colList,
297 int16 *attnums, Oid *atttypids);
298 static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
299 List **attnamelist,
300 int16 *attnums, Oid *atttypids,
301 Oid *opclasses);
302 static Oid transformFkeyCheckAttrs(Relation pkrel,
303 int numattrs, int16 *attnums,
304 Oid *opclasses);
305 static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts);
306 static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId,
307 Oid *funcid);
308 static void validateForeignKeyConstraint(char *conname,
309 Relation rel, Relation pkrel,
310 Oid pkindOid, Oid constraintOid);
311 static void createForeignKeyTriggers(Relation rel, Oid refRelOid,
312 Constraint *fkconstraint,
313 Oid constraintOid, Oid indexOid);
314 static void ATController(AlterTableStmt *parsetree,
315 Relation rel, List *cmds, bool recurse, LOCKMODE lockmode);
316 static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
317 bool recurse, bool recursing, LOCKMODE lockmode);
318 static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode);
319 static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
320 AlterTableCmd *cmd, LOCKMODE lockmode);
321 static void ATRewriteTables(AlterTableStmt *parsetree,
322 List **wqueue, LOCKMODE lockmode);
323 static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode);
324 static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel);
325 static void ATSimplePermissions(Relation rel, int allowed_targets);
326 static void ATWrongRelkindError(Relation rel, int allowed_targets);
327 static void ATSimpleRecursion(List **wqueue, Relation rel,
328 AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode);
329 static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
330 LOCKMODE lockmode);
331 static List *find_typed_table_dependencies(Oid typeOid, const char *typeName,
332 DropBehavior behavior);
333 static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
334 bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode);
335 static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab,
336 Relation rel, ColumnDef *colDef, bool isOid,
337 bool recurse, bool recursing,
338 bool if_not_exists, LOCKMODE lockmode);
339 static bool check_for_column_name_collision(Relation rel, const char *colname,
340 bool if_not_exists);
341 static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid);
342 static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid);
343 static void ATPrepAddOids(List **wqueue, Relation rel, bool recurse,
344 AlterTableCmd *cmd, LOCKMODE lockmode);
345 static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode);
346 static ObjectAddress ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
347 const char *colName, LOCKMODE lockmode);
348 static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName,
349 Node *newDefault, LOCKMODE lockmode);
350 static void ATPrepSetStatistics(Relation rel, const char *colName,
351 Node *newValue, LOCKMODE lockmode);
352 static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName,
353 Node *newValue, LOCKMODE lockmode);
354 static ObjectAddress ATExecSetOptions(Relation rel, const char *colName,
355 Node *options, bool isReset, LOCKMODE lockmode);
356 static ObjectAddress ATExecSetStorage(Relation rel, const char *colName,
357 Node *newValue, LOCKMODE lockmode);
358 static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
359 AlterTableCmd *cmd, LOCKMODE lockmode);
360 static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
361 DropBehavior behavior,
362 bool recurse, bool recursing,
363 bool missing_ok, LOCKMODE lockmode);
364 static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
365 IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode);
366 static ObjectAddress ATExecAddConstraint(List **wqueue,
367 AlteredTableInfo *tab, Relation rel,
368 Constraint *newConstraint, bool recurse, bool is_readd,
369 LOCKMODE lockmode);
370 static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
371 IndexStmt *stmt, LOCKMODE lockmode);
372 static ObjectAddress ATAddCheckConstraint(List **wqueue,
373 AlteredTableInfo *tab, Relation rel,
374 Constraint *constr,
375 bool recurse, bool recursing, bool is_readd,
376 LOCKMODE lockmode);
377 static ObjectAddress ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel,
378 Constraint *fkconstraint, LOCKMODE lockmode);
379 static void ATExecDropConstraint(Relation rel, const char *constrName,
380 DropBehavior behavior,
381 bool recurse, bool recursing,
382 bool missing_ok, LOCKMODE lockmode);
383 static void ATPrepAlterColumnType(List **wqueue,
384 AlteredTableInfo *tab, Relation rel,
385 bool recurse, bool recursing,
386 AlterTableCmd *cmd, LOCKMODE lockmode);
387 static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno);
388 static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
389 AlterTableCmd *cmd, LOCKMODE lockmode);
390 static void RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab,
391 DependencyType deptype);
392 static void RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab);
393 static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName,
394 List *options, LOCKMODE lockmode);
395 static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab,
396 LOCKMODE lockmode);
397 static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId,
398 char *cmd, List **wqueue, LOCKMODE lockmode,
399 bool rewrite);
400 static void RebuildConstraintComment(AlteredTableInfo *tab, int pass,
401 Oid objid, Relation rel, char *conname);
402 static void TryReuseIndex(Oid oldId, IndexStmt *stmt);
403 static void TryReuseForeignKey(Oid oldId, Constraint *con);
404 static void change_owner_fix_column_acls(Oid relationOid,
405 Oid oldOwnerId, Oid newOwnerId);
406 static void change_owner_recurse_to_sequences(Oid relationOid,
407 Oid newOwnerId, LOCKMODE lockmode);
408 static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName,
409 LOCKMODE lockmode);
410 static void ATExecDropCluster(Relation rel, LOCKMODE lockmode);
411 static bool ATPrepChangePersistence(Relation rel, bool toLogged);
412 static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
413 char *tablespacename, LOCKMODE lockmode);
414 static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
415 static void ATExecSetRelOptions(Relation rel, List *defList,
416 AlterTableType operation,
417 LOCKMODE lockmode);
418 static void ATExecEnableDisableTrigger(Relation rel, char *trigname,
419 char fires_when, bool skip_system, LOCKMODE lockmode);
420 static void ATExecEnableDisableRule(Relation rel, char *rulename,
421 char fires_when, LOCKMODE lockmode);
422 static void ATPrepAddInherit(Relation child_rel);
423 static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode);
424 static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode);
425 static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid);
426 static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode);
427 static void ATExecDropOf(Relation rel, LOCKMODE lockmode);
428 static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode);
429 static void ATExecGenericOptions(Relation rel, List *options);
430 static void ATExecEnableRowSecurity(Relation rel);
431 static void ATExecDisableRowSecurity(Relation rel);
432 static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
433
434 static void copy_relation_data(SMgrRelation rel, SMgrRelation dst,
435 ForkNumber forkNum, char relpersistence);
436 static const char *storage_name(char c);
437
438 static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid,
439 Oid oldRelOid, void *arg);
440 static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid,
441 Oid oldrelid, void *arg);
442
443
444 /* ----------------------------------------------------------------
445 * DefineRelation
446 * Creates a new relation.
447 *
448 * stmt carries parsetree information from an ordinary CREATE TABLE statement.
449 * The other arguments are used to extend the behavior for other cases:
450 * relkind: relkind to assign to the new relation
451 * ownerId: if not InvalidOid, use this as the new relation's owner.
452 * typaddress: if not null, it's set to the pg_type entry's address.
453 *
454 * Note that permissions checks are done against current user regardless of
455 * ownerId. A nonzero ownerId is used when someone is creating a relation
456 * "on behalf of" someone else, so we still want to see that the current user
457 * has permissions to do it.
458 *
459 * If successful, returns the address of the new relation.
460 * ----------------------------------------------------------------
461 */
462 ObjectAddress
DefineRelation(CreateStmt * stmt,char relkind,Oid ownerId,ObjectAddress * typaddress)463 DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
464 ObjectAddress *typaddress)
465 {
466 char relname[NAMEDATALEN];
467 Oid namespaceId;
468 List *schema = stmt->tableElts;
469 Oid relationId;
470 Oid tablespaceId;
471 Relation rel;
472 TupleDesc descriptor;
473 List *inheritOids;
474 List *old_constraints;
475 bool localHasOids;
476 int parentOidCount;
477 List *rawDefaults;
478 List *cookedDefaults;
479 Datum reloptions;
480 ListCell *listptr;
481 AttrNumber attnum;
482 static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
483 Oid ofTypeId;
484 ObjectAddress address;
485
486 /*
487 * Truncate relname to appropriate length (probably a waste of time, as
488 * parser should have done this already).
489 */
490 StrNCpy(relname, stmt->relation->relname, NAMEDATALEN);
491
492 /*
493 * Check consistency of arguments
494 */
495 if (stmt->oncommit != ONCOMMIT_NOOP
496 && stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
497 ereport(ERROR,
498 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
499 errmsg("ON COMMIT can only be used on temporary tables")));
500
501 /*
502 * Look up the namespace in which we are supposed to create the relation,
503 * check we have permission to create there, lock it against concurrent
504 * drop, and mark stmt->relation as RELPERSISTENCE_TEMP if a temporary
505 * namespace is selected.
506 */
507 namespaceId =
508 RangeVarGetAndCheckCreationNamespace(stmt->relation, NoLock, NULL);
509
510 /*
511 * Security check: disallow creating temp tables from security-restricted
512 * code. This is needed because calling code might not expect untrusted
513 * tables to appear in pg_temp at the front of its search path.
514 */
515 if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP
516 && InSecurityRestrictedOperation())
517 ereport(ERROR,
518 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
519 errmsg("cannot create temporary table within security-restricted operation")));
520
521 /*
522 * Select tablespace to use. If not specified, use default tablespace
523 * (which may in turn default to database's default).
524 */
525 if (stmt->tablespacename)
526 {
527 tablespaceId = get_tablespace_oid(stmt->tablespacename, false);
528 }
529 else
530 {
531 tablespaceId = GetDefaultTablespace(stmt->relation->relpersistence);
532 /* note InvalidOid is OK in this case */
533 }
534
535 /* Check permissions except when using database's default */
536 if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
537 {
538 AclResult aclresult;
539
540 aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
541 ACL_CREATE);
542 if (aclresult != ACLCHECK_OK)
543 aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
544 get_tablespace_name(tablespaceId));
545 }
546
547 /* In all cases disallow placing user relations in pg_global */
548 if (tablespaceId == GLOBALTABLESPACE_OID)
549 ereport(ERROR,
550 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
551 errmsg("only shared relations can be placed in pg_global tablespace")));
552
553 /* Identify user ID that will own the table */
554 if (!OidIsValid(ownerId))
555 ownerId = GetUserId();
556
557 /*
558 * Parse and validate reloptions, if any.
559 */
560 reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
561 true, false);
562
563 if (relkind == RELKIND_VIEW)
564 (void) view_reloptions(reloptions, true);
565 else
566 (void) heap_reloptions(relkind, reloptions, true);
567
568 if (stmt->ofTypename)
569 {
570 AclResult aclresult;
571
572 ofTypeId = typenameTypeId(NULL, stmt->ofTypename);
573
574 aclresult = pg_type_aclcheck(ofTypeId, GetUserId(), ACL_USAGE);
575 if (aclresult != ACLCHECK_OK)
576 aclcheck_error_type(aclresult, ofTypeId);
577 }
578 else
579 ofTypeId = InvalidOid;
580
581 /*
582 * Look up inheritance ancestors and generate relation schema, including
583 * inherited attributes.
584 */
585 schema = MergeAttributes(schema, stmt->inhRelations,
586 stmt->relation->relpersistence,
587 &inheritOids, &old_constraints, &parentOidCount);
588
589 /*
590 * Create a tuple descriptor from the relation schema. Note that this
591 * deals with column names, types, and NOT NULL constraints, but not
592 * default values or CHECK constraints; we handle those below.
593 */
594 descriptor = BuildDescForRelation(schema);
595
596 /*
597 * Notice that we allow OIDs here only for plain tables, even though some
598 * other relkinds can support them. This is necessary because the
599 * default_with_oids GUC must apply only to plain tables and not any other
600 * relkind; doing otherwise would break existing pg_dump files. We could
601 * allow explicit "WITH OIDS" while not allowing default_with_oids to
602 * affect other relkinds, but it would complicate interpretOidsOption().
603 */
604 localHasOids = interpretOidsOption(stmt->options,
605 (relkind == RELKIND_RELATION));
606 descriptor->tdhasoid = (localHasOids || parentOidCount > 0);
607
608 /*
609 * Find columns with default values and prepare for insertion of the
610 * defaults. Pre-cooked (that is, inherited) defaults go into a list of
611 * CookedConstraint structs that we'll pass to heap_create_with_catalog,
612 * while raw defaults go into a list of RawColumnDefault structs that will
613 * be processed by AddRelationNewConstraints. (We can't deal with raw
614 * expressions until we can do transformExpr.)
615 *
616 * We can set the atthasdef flags now in the tuple descriptor; this just
617 * saves StoreAttrDefault from having to do an immediate update of the
618 * pg_attribute rows.
619 */
620 rawDefaults = NIL;
621 cookedDefaults = NIL;
622 attnum = 0;
623
624 foreach(listptr, schema)
625 {
626 ColumnDef *colDef = lfirst(listptr);
627
628 attnum++;
629
630 if (colDef->raw_default != NULL)
631 {
632 RawColumnDefault *rawEnt;
633
634 Assert(colDef->cooked_default == NULL);
635
636 rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
637 rawEnt->attnum = attnum;
638 rawEnt->raw_default = colDef->raw_default;
639 rawDefaults = lappend(rawDefaults, rawEnt);
640 descriptor->attrs[attnum - 1]->atthasdef = true;
641 }
642 else if (colDef->cooked_default != NULL)
643 {
644 CookedConstraint *cooked;
645
646 cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
647 cooked->contype = CONSTR_DEFAULT;
648 cooked->conoid = InvalidOid; /* until created */
649 cooked->name = NULL;
650 cooked->attnum = attnum;
651 cooked->expr = colDef->cooked_default;
652 cooked->skip_validation = false;
653 cooked->is_local = true; /* not used for defaults */
654 cooked->inhcount = 0; /* ditto */
655 cooked->is_no_inherit = false;
656 cookedDefaults = lappend(cookedDefaults, cooked);
657 descriptor->attrs[attnum - 1]->atthasdef = true;
658 }
659 }
660
661 /*
662 * Create the relation. Inherited defaults and constraints are passed in
663 * for immediate handling --- since they don't need parsing, they can be
664 * stored immediately.
665 */
666 relationId = heap_create_with_catalog(relname,
667 namespaceId,
668 tablespaceId,
669 InvalidOid,
670 InvalidOid,
671 ofTypeId,
672 ownerId,
673 descriptor,
674 list_concat(cookedDefaults,
675 old_constraints),
676 relkind,
677 stmt->relation->relpersistence,
678 false,
679 false,
680 localHasOids,
681 parentOidCount,
682 stmt->oncommit,
683 reloptions,
684 true,
685 allowSystemTableMods,
686 false,
687 typaddress);
688
689 /* Store inheritance information for new rel. */
690 StoreCatalogInheritance(relationId, inheritOids);
691
692 /*
693 * We must bump the command counter to make the newly-created relation
694 * tuple visible for opening.
695 */
696 CommandCounterIncrement();
697
698 /*
699 * Open the new relation and acquire exclusive lock on it. This isn't
700 * really necessary for locking out other backends (since they can't see
701 * the new rel anyway until we commit), but it keeps the lock manager from
702 * complaining about deadlock risks.
703 */
704 rel = relation_open(relationId, AccessExclusiveLock);
705
706 /*
707 * Now add any newly specified column default values and CHECK constraints
708 * to the new relation. These are passed to us in the form of raw
709 * parsetrees; we need to transform them to executable expression trees
710 * before they can be added. The most convenient way to do that is to
711 * apply the parser's transformExpr routine, but transformExpr doesn't
712 * work unless we have a pre-existing relation. So, the transformation has
713 * to be postponed to this final step of CREATE TABLE.
714 */
715 if (rawDefaults || stmt->constraints)
716 AddRelationNewConstraints(rel, rawDefaults, stmt->constraints,
717 true, true, false);
718
719 ObjectAddressSet(address, RelationRelationId, relationId);
720
721 /*
722 * Clean up. We keep lock on new relation (although it shouldn't be
723 * visible to anyone else anyway, until commit).
724 */
725 relation_close(rel, NoLock);
726
727 return address;
728 }
729
730 /*
731 * Emit the right error or warning message for a "DROP" command issued on a
732 * non-existent relation
733 */
734 static void
DropErrorMsgNonExistent(RangeVar * rel,char rightkind,bool missing_ok)735 DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok)
736 {
737 const struct dropmsgstrings *rentry;
738
739 if (rel->schemaname != NULL &&
740 !OidIsValid(LookupNamespaceNoError(rel->schemaname)))
741 {
742 if (!missing_ok)
743 {
744 ereport(ERROR,
745 (errcode(ERRCODE_UNDEFINED_SCHEMA),
746 errmsg("schema \"%s\" does not exist", rel->schemaname)));
747 }
748 else
749 {
750 ereport(NOTICE,
751 (errmsg("schema \"%s\" does not exist, skipping",
752 rel->schemaname)));
753 }
754 return;
755 }
756
757 for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
758 {
759 if (rentry->kind == rightkind)
760 {
761 if (!missing_ok)
762 {
763 ereport(ERROR,
764 (errcode(rentry->nonexistent_code),
765 errmsg(rentry->nonexistent_msg, rel->relname)));
766 }
767 else
768 {
769 ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname)));
770 break;
771 }
772 }
773 }
774
775 Assert(rentry->kind != '\0'); /* Should be impossible */
776 }
777
778 /*
779 * Emit the right error message for a "DROP" command issued on a
780 * relation of the wrong type
781 */
782 static void
DropErrorMsgWrongType(const char * relname,char wrongkind,char rightkind)783 DropErrorMsgWrongType(const char *relname, char wrongkind, char rightkind)
784 {
785 const struct dropmsgstrings *rentry;
786 const struct dropmsgstrings *wentry;
787
788 for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
789 if (rentry->kind == rightkind)
790 break;
791 Assert(rentry->kind != '\0');
792
793 for (wentry = dropmsgstringarray; wentry->kind != '\0'; wentry++)
794 if (wentry->kind == wrongkind)
795 break;
796 /* wrongkind could be something we don't have in our table... */
797
798 ereport(ERROR,
799 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
800 errmsg(rentry->nota_msg, relname),
801 (wentry->kind != '\0') ? errhint("%s", _(wentry->drophint_msg)) : 0));
802 }
803
804 /*
805 * RemoveRelations
806 * Implements DROP TABLE, DROP INDEX, DROP SEQUENCE, DROP VIEW,
807 * DROP MATERIALIZED VIEW, DROP FOREIGN TABLE
808 */
809 void
RemoveRelations(DropStmt * drop)810 RemoveRelations(DropStmt *drop)
811 {
812 ObjectAddresses *objects;
813 char relkind;
814 ListCell *cell;
815 int flags = 0;
816 LOCKMODE lockmode = AccessExclusiveLock;
817
818 /* DROP CONCURRENTLY uses a weaker lock, and has some restrictions */
819 if (drop->concurrent)
820 {
821 /*
822 * Note that for temporary relations this lock may get upgraded
823 * later on, but as no other session can access a temporary
824 * relation, this is actually fine.
825 */
826 lockmode = ShareUpdateExclusiveLock;
827 Assert(drop->removeType == OBJECT_INDEX);
828 if (list_length(drop->objects) != 1)
829 ereport(ERROR,
830 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
831 errmsg("DROP INDEX CONCURRENTLY does not support dropping multiple objects")));
832 if (drop->behavior == DROP_CASCADE)
833 ereport(ERROR,
834 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
835 errmsg("DROP INDEX CONCURRENTLY does not support CASCADE")));
836 }
837
838 /*
839 * First we identify all the relations, then we delete them in a single
840 * performMultipleDeletions() call. This is to avoid unwanted DROP
841 * RESTRICT errors if one of the relations depends on another.
842 */
843
844 /* Determine required relkind */
845 switch (drop->removeType)
846 {
847 case OBJECT_TABLE:
848 relkind = RELKIND_RELATION;
849 break;
850
851 case OBJECT_INDEX:
852 relkind = RELKIND_INDEX;
853 break;
854
855 case OBJECT_SEQUENCE:
856 relkind = RELKIND_SEQUENCE;
857 break;
858
859 case OBJECT_VIEW:
860 relkind = RELKIND_VIEW;
861 break;
862
863 case OBJECT_MATVIEW:
864 relkind = RELKIND_MATVIEW;
865 break;
866
867 case OBJECT_FOREIGN_TABLE:
868 relkind = RELKIND_FOREIGN_TABLE;
869 break;
870
871 default:
872 elog(ERROR, "unrecognized drop object type: %d",
873 (int) drop->removeType);
874 relkind = 0; /* keep compiler quiet */
875 break;
876 }
877
878 /* Lock and validate each relation; build a list of object addresses */
879 objects = new_object_addresses();
880
881 foreach(cell, drop->objects)
882 {
883 RangeVar *rel = makeRangeVarFromNameList((List *) lfirst(cell));
884 Oid relOid;
885 ObjectAddress obj;
886 struct DropRelationCallbackState state;
887
888 /*
889 * These next few steps are a great deal like relation_openrv, but we
890 * don't bother building a relcache entry since we don't need it.
891 *
892 * Check for shared-cache-inval messages before trying to access the
893 * relation. This is needed to cover the case where the name
894 * identifies a rel that has been dropped and recreated since the
895 * start of our transaction: if we don't flush the old syscache entry,
896 * then we'll latch onto that entry and suffer an error later.
897 */
898 AcceptInvalidationMessages();
899
900 /* Look up the appropriate relation using namespace search. */
901 state.relkind = relkind;
902 state.heapOid = InvalidOid;
903 state.concurrent = drop->concurrent;
904 relOid = RangeVarGetRelidExtended(rel, lockmode, true,
905 false,
906 RangeVarCallbackForDropRelation,
907 (void *) &state);
908
909 /* Not there? */
910 if (!OidIsValid(relOid))
911 {
912 DropErrorMsgNonExistent(rel, relkind, drop->missing_ok);
913 continue;
914 }
915
916 /*
917 * Decide if concurrent mode needs to be used here or not. The
918 * relation persistence cannot be known without its OID.
919 */
920 if (drop->concurrent &&
921 get_rel_persistence(relOid) != RELPERSISTENCE_TEMP)
922 {
923 Assert(list_length(drop->objects) == 1 &&
924 drop->removeType == OBJECT_INDEX);
925 flags |= PERFORM_DELETION_CONCURRENTLY;
926 }
927
928 /* OK, we're ready to delete this one */
929 obj.classId = RelationRelationId;
930 obj.objectId = relOid;
931 obj.objectSubId = 0;
932
933 add_exact_object_address(&obj, objects);
934 }
935
936 performMultipleDeletions(objects, drop->behavior, flags);
937
938 free_object_addresses(objects);
939 }
940
941 /*
942 * Before acquiring a table lock, check whether we have sufficient rights.
943 * In the case of DROP INDEX, also try to lock the table before the index.
944 */
945 static void
RangeVarCallbackForDropRelation(const RangeVar * rel,Oid relOid,Oid oldRelOid,void * arg)946 RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid,
947 void *arg)
948 {
949 HeapTuple tuple;
950 struct DropRelationCallbackState *state;
951 char relkind;
952 Form_pg_class classform;
953 LOCKMODE heap_lockmode;
954
955 state = (struct DropRelationCallbackState *) arg;
956 relkind = state->relkind;
957 heap_lockmode = state->concurrent ?
958 ShareUpdateExclusiveLock : AccessExclusiveLock;
959
960 /*
961 * If we previously locked some other index's heap, and the name we're
962 * looking up no longer refers to that relation, release the now-useless
963 * lock.
964 */
965 if (relOid != oldRelOid && OidIsValid(state->heapOid))
966 {
967 UnlockRelationOid(state->heapOid, heap_lockmode);
968 state->heapOid = InvalidOid;
969 }
970
971 /* Didn't find a relation, so no need for locking or permission checks. */
972 if (!OidIsValid(relOid))
973 return;
974
975 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
976 if (!HeapTupleIsValid(tuple))
977 return; /* concurrently dropped, so nothing to do */
978 classform = (Form_pg_class) GETSTRUCT(tuple);
979
980 if (classform->relkind != relkind)
981 DropErrorMsgWrongType(rel->relname, classform->relkind, relkind);
982
983 /* Allow DROP to either table owner or schema owner */
984 if (!pg_class_ownercheck(relOid, GetUserId()) &&
985 !pg_namespace_ownercheck(classform->relnamespace, GetUserId()))
986 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
987 rel->relname);
988
989 if (!allowSystemTableMods && IsSystemClass(relOid, classform))
990 ereport(ERROR,
991 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
992 errmsg("permission denied: \"%s\" is a system catalog",
993 rel->relname)));
994
995 ReleaseSysCache(tuple);
996
997 /*
998 * In DROP INDEX, attempt to acquire lock on the parent table before
999 * locking the index. index_drop() will need this anyway, and since
1000 * regular queries lock tables before their indexes, we risk deadlock if
1001 * we do it the other way around. No error if we don't find a pg_index
1002 * entry, though --- the relation may have been dropped.
1003 */
1004 if (relkind == RELKIND_INDEX && relOid != oldRelOid)
1005 {
1006 state->heapOid = IndexGetRelation(relOid, true);
1007 if (OidIsValid(state->heapOid))
1008 LockRelationOid(state->heapOid, heap_lockmode);
1009 }
1010 }
1011
1012 /*
1013 * ExecuteTruncate
1014 * Executes a TRUNCATE command.
1015 *
1016 * This is a multi-relation truncate. We first open and grab exclusive
1017 * lock on all relations involved, checking permissions and otherwise
1018 * verifying that the relation is OK for truncation. In CASCADE mode,
1019 * relations having FK references to the targeted relations are automatically
1020 * added to the group; in RESTRICT mode, we check that all FK references are
1021 * internal to the group that's being truncated. Finally all the relations
1022 * are truncated and reindexed.
1023 */
1024 void
ExecuteTruncate(TruncateStmt * stmt)1025 ExecuteTruncate(TruncateStmt *stmt)
1026 {
1027 List *rels = NIL;
1028 List *relids = NIL;
1029 List *seq_relids = NIL;
1030 EState *estate;
1031 ResultRelInfo *resultRelInfos;
1032 ResultRelInfo *resultRelInfo;
1033 SubTransactionId mySubid;
1034 ListCell *cell;
1035
1036 /*
1037 * Open, exclusive-lock, and check all the explicitly-specified relations
1038 */
1039 foreach(cell, stmt->relations)
1040 {
1041 RangeVar *rv = lfirst(cell);
1042 Relation rel;
1043 bool recurse = interpretInhOption(rv->inhOpt);
1044 Oid myrelid;
1045 LOCKMODE lockmode = AccessExclusiveLock;
1046
1047 rel = heap_openrv(rv, lockmode);
1048 myrelid = RelationGetRelid(rel);
1049 /* don't throw error for "TRUNCATE foo, foo" */
1050 if (list_member_oid(relids, myrelid))
1051 {
1052 heap_close(rel, lockmode);
1053 continue;
1054 }
1055 truncate_check_rel(rel);
1056 rels = lappend(rels, rel);
1057 relids = lappend_oid(relids, myrelid);
1058
1059 if (recurse)
1060 {
1061 ListCell *child;
1062 List *children;
1063
1064 children = find_all_inheritors(myrelid, lockmode, NULL);
1065
1066 foreach(child, children)
1067 {
1068 Oid childrelid = lfirst_oid(child);
1069
1070 if (list_member_oid(relids, childrelid))
1071 continue;
1072
1073 /* find_all_inheritors already got lock */
1074 rel = heap_open(childrelid, NoLock);
1075
1076 /*
1077 * It is possible that the parent table has children that are
1078 * temp tables of other backends. We cannot safely access
1079 * such tables (because of buffering issues), and the best
1080 * thing to do is to silently ignore them. Note that this
1081 * check is the same as one of the checks done in
1082 * truncate_check_rel() called below, still it is kept
1083 * here for simplicity.
1084 */
1085 if (RELATION_IS_OTHER_TEMP(rel))
1086 {
1087 heap_close(rel, lockmode);
1088 continue;
1089 }
1090
1091 truncate_check_rel(rel);
1092 rels = lappend(rels, rel);
1093 relids = lappend_oid(relids, childrelid);
1094 }
1095 }
1096 }
1097
1098 /*
1099 * In CASCADE mode, suck in all referencing relations as well. This
1100 * requires multiple iterations to find indirectly-dependent relations. At
1101 * each phase, we need to exclusive-lock new rels before looking for their
1102 * dependencies, else we might miss something. Also, we check each rel as
1103 * soon as we open it, to avoid a faux pas such as holding lock for a long
1104 * time on a rel we have no permissions for.
1105 */
1106 if (stmt->behavior == DROP_CASCADE)
1107 {
1108 for (;;)
1109 {
1110 List *newrelids;
1111
1112 newrelids = heap_truncate_find_FKs(relids);
1113 if (newrelids == NIL)
1114 break; /* nothing else to add */
1115
1116 foreach(cell, newrelids)
1117 {
1118 Oid relid = lfirst_oid(cell);
1119 Relation rel;
1120
1121 rel = heap_open(relid, AccessExclusiveLock);
1122 ereport(NOTICE,
1123 (errmsg("truncate cascades to table \"%s\"",
1124 RelationGetRelationName(rel))));
1125 truncate_check_rel(rel);
1126 rels = lappend(rels, rel);
1127 relids = lappend_oid(relids, relid);
1128 }
1129 }
1130 }
1131
1132 /*
1133 * Check foreign key references. In CASCADE mode, this should be
1134 * unnecessary since we just pulled in all the references; but as a
1135 * cross-check, do it anyway if in an Assert-enabled build.
1136 */
1137 #ifdef USE_ASSERT_CHECKING
1138 heap_truncate_check_FKs(rels, false);
1139 #else
1140 if (stmt->behavior == DROP_RESTRICT)
1141 heap_truncate_check_FKs(rels, false);
1142 #endif
1143
1144 /*
1145 * If we are asked to restart sequences, find all the sequences, lock them
1146 * (we need AccessExclusiveLock for ResetSequence), and check permissions.
1147 * We want to do this early since it's pointless to do all the truncation
1148 * work only to fail on sequence permissions.
1149 */
1150 if (stmt->restart_seqs)
1151 {
1152 foreach(cell, rels)
1153 {
1154 Relation rel = (Relation) lfirst(cell);
1155 List *seqlist = getOwnedSequences(RelationGetRelid(rel));
1156 ListCell *seqcell;
1157
1158 foreach(seqcell, seqlist)
1159 {
1160 Oid seq_relid = lfirst_oid(seqcell);
1161 Relation seq_rel;
1162
1163 seq_rel = relation_open(seq_relid, AccessExclusiveLock);
1164
1165 /* This check must match AlterSequence! */
1166 if (!pg_class_ownercheck(seq_relid, GetUserId()))
1167 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
1168 RelationGetRelationName(seq_rel));
1169
1170 seq_relids = lappend_oid(seq_relids, seq_relid);
1171
1172 relation_close(seq_rel, NoLock);
1173 }
1174 }
1175 }
1176
1177 /* Prepare to catch AFTER triggers. */
1178 AfterTriggerBeginQuery();
1179
1180 /*
1181 * To fire triggers, we'll need an EState as well as a ResultRelInfo for
1182 * each relation. We don't need to call ExecOpenIndices, though.
1183 */
1184 estate = CreateExecutorState();
1185 resultRelInfos = (ResultRelInfo *)
1186 palloc(list_length(rels) * sizeof(ResultRelInfo));
1187 resultRelInfo = resultRelInfos;
1188 foreach(cell, rels)
1189 {
1190 Relation rel = (Relation) lfirst(cell);
1191
1192 InitResultRelInfo(resultRelInfo,
1193 rel,
1194 0, /* dummy rangetable index */
1195 0);
1196 resultRelInfo++;
1197 }
1198 estate->es_result_relations = resultRelInfos;
1199 estate->es_num_result_relations = list_length(rels);
1200
1201 /*
1202 * Process all BEFORE STATEMENT TRUNCATE triggers before we begin
1203 * truncating (this is because one of them might throw an error). Also, if
1204 * we were to allow them to prevent statement execution, that would need
1205 * to be handled here.
1206 */
1207 resultRelInfo = resultRelInfos;
1208 foreach(cell, rels)
1209 {
1210 estate->es_result_relation_info = resultRelInfo;
1211 ExecBSTruncateTriggers(estate, resultRelInfo);
1212 resultRelInfo++;
1213 }
1214
1215 /*
1216 * OK, truncate each table.
1217 */
1218 mySubid = GetCurrentSubTransactionId();
1219
1220 foreach(cell, rels)
1221 {
1222 Relation rel = (Relation) lfirst(cell);
1223
1224 /*
1225 * Normally, we need a transaction-safe truncation here. However, if
1226 * the table was either created in the current (sub)transaction or has
1227 * a new relfilenode in the current (sub)transaction, then we can just
1228 * truncate it in-place, because a rollback would cause the whole
1229 * table or the current physical file to be thrown away anyway.
1230 */
1231 if (rel->rd_createSubid == mySubid ||
1232 rel->rd_newRelfilenodeSubid == mySubid)
1233 {
1234 /* Immediate, non-rollbackable truncation is OK */
1235 heap_truncate_one_rel(rel);
1236 }
1237 else
1238 {
1239 Oid heap_relid;
1240 Oid toast_relid;
1241 MultiXactId minmulti;
1242
1243 /*
1244 * This effectively deletes all rows in the table, and may be done
1245 * in a serializable transaction. In that case we must record a
1246 * rw-conflict in to this transaction from each transaction
1247 * holding a predicate lock on the table.
1248 */
1249 CheckTableForSerializableConflictIn(rel);
1250
1251 minmulti = GetOldestMultiXactId();
1252
1253 /*
1254 * Need the full transaction-safe pushups.
1255 *
1256 * Create a new empty storage file for the relation, and assign it
1257 * as the relfilenode value. The old storage file is scheduled for
1258 * deletion at commit.
1259 */
1260 RelationSetNewRelfilenode(rel, rel->rd_rel->relpersistence,
1261 RecentXmin, minmulti);
1262 if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
1263 heap_create_init_fork(rel);
1264
1265 heap_relid = RelationGetRelid(rel);
1266
1267 /*
1268 * The same for the toast table, if any.
1269 */
1270 toast_relid = rel->rd_rel->reltoastrelid;
1271 if (OidIsValid(toast_relid))
1272 {
1273 Relation toastrel = relation_open(toast_relid,
1274 AccessExclusiveLock);
1275
1276 RelationSetNewRelfilenode(toastrel,
1277 toastrel->rd_rel->relpersistence,
1278 RecentXmin, minmulti);
1279 if (toastrel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
1280 heap_create_init_fork(toastrel);
1281 heap_close(toastrel, NoLock);
1282 }
1283
1284 /*
1285 * Reconstruct the indexes to match, and we're done.
1286 */
1287 reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST, 0);
1288 }
1289
1290 pgstat_count_truncate(rel);
1291 }
1292
1293 /*
1294 * Restart owned sequences if we were asked to.
1295 */
1296 foreach(cell, seq_relids)
1297 {
1298 Oid seq_relid = lfirst_oid(cell);
1299
1300 ResetSequence(seq_relid);
1301 }
1302
1303 /*
1304 * Process all AFTER STATEMENT TRUNCATE triggers.
1305 */
1306 resultRelInfo = resultRelInfos;
1307 foreach(cell, rels)
1308 {
1309 estate->es_result_relation_info = resultRelInfo;
1310 ExecASTruncateTriggers(estate, resultRelInfo);
1311 resultRelInfo++;
1312 }
1313
1314 /* Handle queued AFTER triggers */
1315 AfterTriggerEndQuery(estate);
1316
1317 /* We can clean up the EState now */
1318 FreeExecutorState(estate);
1319
1320 /* And close the rels (can't do this while EState still holds refs) */
1321 foreach(cell, rels)
1322 {
1323 Relation rel = (Relation) lfirst(cell);
1324
1325 heap_close(rel, NoLock);
1326 }
1327 }
1328
1329 /*
1330 * Check that a given rel is safe to truncate. Subroutine for ExecuteTruncate
1331 */
1332 static void
truncate_check_rel(Relation rel)1333 truncate_check_rel(Relation rel)
1334 {
1335 AclResult aclresult;
1336
1337 /* Only allow truncate on regular tables */
1338 if (rel->rd_rel->relkind != RELKIND_RELATION)
1339 ereport(ERROR,
1340 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1341 errmsg("\"%s\" is not a table",
1342 RelationGetRelationName(rel))));
1343
1344 /* Permissions checks */
1345 aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
1346 ACL_TRUNCATE);
1347 if (aclresult != ACLCHECK_OK)
1348 aclcheck_error(aclresult, ACL_KIND_CLASS,
1349 RelationGetRelationName(rel));
1350
1351 if (!allowSystemTableMods && IsSystemRelation(rel))
1352 ereport(ERROR,
1353 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
1354 errmsg("permission denied: \"%s\" is a system catalog",
1355 RelationGetRelationName(rel))));
1356
1357 /*
1358 * Don't allow truncate on temp tables of other backends ... their local
1359 * buffer manager is not going to cope.
1360 */
1361 if (RELATION_IS_OTHER_TEMP(rel))
1362 ereport(ERROR,
1363 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1364 errmsg("cannot truncate temporary tables of other sessions")));
1365
1366 /*
1367 * Also check for active uses of the relation in the current transaction,
1368 * including open scans and pending AFTER trigger events.
1369 */
1370 CheckTableNotInUse(rel, "TRUNCATE");
1371 }
1372
1373 /*
1374 * storage_name
1375 * returns the name corresponding to a typstorage/attstorage enum value
1376 */
1377 static const char *
storage_name(char c)1378 storage_name(char c)
1379 {
1380 switch (c)
1381 {
1382 case 'p':
1383 return "PLAIN";
1384 case 'm':
1385 return "MAIN";
1386 case 'x':
1387 return "EXTENDED";
1388 case 'e':
1389 return "EXTERNAL";
1390 default:
1391 return "???";
1392 }
1393 }
1394
1395 /*----------
1396 * MergeAttributes
1397 * Returns new schema given initial schema and superclasses.
1398 *
1399 * Input arguments:
1400 * 'schema' is the column/attribute definition for the table. (It's a list
1401 * of ColumnDef's.) It is destructively changed.
1402 * 'supers' is a list of names (as RangeVar nodes) of parent relations.
1403 * 'relpersistence' is a persistence type of the table.
1404 *
1405 * Output arguments:
1406 * 'supOids' receives a list of the OIDs of the parent relations.
1407 * 'supconstr' receives a list of constraints belonging to the parents,
1408 * updated as necessary to be valid for the child.
1409 * 'supOidCount' is set to the number of parents that have OID columns.
1410 *
1411 * Return value:
1412 * Completed schema list.
1413 *
1414 * Notes:
1415 * The order in which the attributes are inherited is very important.
1416 * Intuitively, the inherited attributes should come first. If a table
1417 * inherits from multiple parents, the order of those attributes are
1418 * according to the order of the parents specified in CREATE TABLE.
1419 *
1420 * Here's an example:
1421 *
1422 * create table person (name text, age int4, location point);
1423 * create table emp (salary int4, manager text) inherits(person);
1424 * create table student (gpa float8) inherits (person);
1425 * create table stud_emp (percent int4) inherits (emp, student);
1426 *
1427 * The order of the attributes of stud_emp is:
1428 *
1429 * person {1:name, 2:age, 3:location}
1430 * / \
1431 * {6:gpa} student emp {4:salary, 5:manager}
1432 * \ /
1433 * stud_emp {7:percent}
1434 *
1435 * If the same attribute name appears multiple times, then it appears
1436 * in the result table in the proper location for its first appearance.
1437 *
1438 * Constraints (including NOT NULL constraints) for the child table
1439 * are the union of all relevant constraints, from both the child schema
1440 * and parent tables.
1441 *
1442 * The default value for a child column is defined as:
1443 * (1) If the child schema specifies a default, that value is used.
1444 * (2) If neither the child nor any parent specifies a default, then
1445 * the column will not have a default.
1446 * (3) If conflicting defaults are inherited from different parents
1447 * (and not overridden by the child), an error is raised.
1448 * (4) Otherwise the inherited default is used.
1449 * Rule (3) is new in Postgres 7.1; in earlier releases you got a
1450 * rather arbitrary choice of which parent default to use.
1451 *----------
1452 */
1453 static List *
MergeAttributes(List * schema,List * supers,char relpersistence,List ** supOids,List ** supconstr,int * supOidCount)1454 MergeAttributes(List *schema, List *supers, char relpersistence,
1455 List **supOids, List **supconstr, int *supOidCount)
1456 {
1457 ListCell *entry;
1458 List *inhSchema = NIL;
1459 List *parentOids = NIL;
1460 List *constraints = NIL;
1461 int parentsWithOids = 0;
1462 bool have_bogus_defaults = false;
1463 int child_attno;
1464 static Node bogus_marker = {0}; /* marks conflicting defaults */
1465
1466 /*
1467 * Check for and reject tables with too many columns. We perform this
1468 * check relatively early for two reasons: (a) we don't run the risk of
1469 * overflowing an AttrNumber in subsequent code (b) an O(n^2) algorithm is
1470 * okay if we're processing <= 1600 columns, but could take minutes to
1471 * execute if the user attempts to create a table with hundreds of
1472 * thousands of columns.
1473 *
1474 * Note that we also need to check that any we do not exceed this figure
1475 * after including columns from inherited relations.
1476 */
1477 if (list_length(schema) > MaxHeapAttributeNumber)
1478 ereport(ERROR,
1479 (errcode(ERRCODE_TOO_MANY_COLUMNS),
1480 errmsg("tables can have at most %d columns",
1481 MaxHeapAttributeNumber)));
1482
1483 /*
1484 * Check for duplicate names in the explicit list of attributes.
1485 *
1486 * Although we might consider merging such entries in the same way that we
1487 * handle name conflicts for inherited attributes, it seems to make more
1488 * sense to assume such conflicts are errors.
1489 */
1490 foreach(entry, schema)
1491 {
1492 ColumnDef *coldef = lfirst(entry);
1493 ListCell *rest = lnext(entry);
1494 ListCell *prev = entry;
1495
1496 if (coldef->typeName == NULL)
1497
1498 /*
1499 * Typed table column option that does not belong to a column from
1500 * the type. This works because the columns from the type come
1501 * first in the list.
1502 */
1503 ereport(ERROR,
1504 (errcode(ERRCODE_UNDEFINED_COLUMN),
1505 errmsg("column \"%s\" does not exist",
1506 coldef->colname)));
1507
1508 while (rest != NULL)
1509 {
1510 ColumnDef *restdef = lfirst(rest);
1511 ListCell *next = lnext(rest); /* need to save it in case we
1512 * delete it */
1513
1514 if (strcmp(coldef->colname, restdef->colname) == 0)
1515 {
1516 if (coldef->is_from_type)
1517 {
1518 /*
1519 * merge the column options into the column from the type
1520 */
1521 coldef->is_not_null = restdef->is_not_null;
1522 coldef->raw_default = restdef->raw_default;
1523 coldef->cooked_default = restdef->cooked_default;
1524 coldef->constraints = restdef->constraints;
1525 coldef->is_from_type = false;
1526 list_delete_cell(schema, rest, prev);
1527 }
1528 else
1529 ereport(ERROR,
1530 (errcode(ERRCODE_DUPLICATE_COLUMN),
1531 errmsg("column \"%s\" specified more than once",
1532 coldef->colname)));
1533 }
1534 prev = rest;
1535 rest = next;
1536 }
1537 }
1538
1539 /*
1540 * Scan the parents left-to-right, and merge their attributes to form a
1541 * list of inherited attributes (inhSchema). Also check to see if we need
1542 * to inherit an OID column.
1543 */
1544 child_attno = 0;
1545 foreach(entry, supers)
1546 {
1547 RangeVar *parent = (RangeVar *) lfirst(entry);
1548 Relation relation;
1549 TupleDesc tupleDesc;
1550 TupleConstr *constr;
1551 AttrNumber *newattno;
1552 AttrNumber parent_attno;
1553
1554 /*
1555 * A self-exclusive lock is needed here. If two backends attempt to
1556 * add children to the same parent simultaneously, and that parent has
1557 * no pre-existing children, then both will attempt to update the
1558 * parent's relhassubclass field, leading to a "tuple concurrently
1559 * updated" error. Also, this interlocks against a concurrent ANALYZE
1560 * on the parent table, which might otherwise be attempting to clear
1561 * the parent's relhassubclass field, if its previous children were
1562 * recently dropped.
1563 */
1564 relation = heap_openrv(parent, ShareUpdateExclusiveLock);
1565
1566 if (relation->rd_rel->relkind != RELKIND_RELATION &&
1567 relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE)
1568 ereport(ERROR,
1569 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1570 errmsg("inherited relation \"%s\" is not a table or foreign table",
1571 parent->relname)));
1572 /* Permanent rels cannot inherit from temporary ones */
1573 if (relpersistence != RELPERSISTENCE_TEMP &&
1574 relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
1575 ereport(ERROR,
1576 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1577 errmsg("cannot inherit from temporary relation \"%s\"",
1578 parent->relname)));
1579
1580 /* If existing rel is temp, it must belong to this session */
1581 if (relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
1582 !relation->rd_islocaltemp)
1583 ereport(ERROR,
1584 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
1585 errmsg("cannot inherit from temporary relation of another session")));
1586
1587 /*
1588 * We should have an UNDER permission flag for this, but for now,
1589 * demand that creator of a child table own the parent.
1590 */
1591 if (!pg_class_ownercheck(RelationGetRelid(relation), GetUserId()))
1592 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
1593 RelationGetRelationName(relation));
1594
1595 /*
1596 * Reject duplications in the list of parents.
1597 */
1598 if (list_member_oid(parentOids, RelationGetRelid(relation)))
1599 ereport(ERROR,
1600 (errcode(ERRCODE_DUPLICATE_TABLE),
1601 errmsg("relation \"%s\" would be inherited from more than once",
1602 parent->relname)));
1603
1604 parentOids = lappend_oid(parentOids, RelationGetRelid(relation));
1605
1606 if (relation->rd_rel->relhasoids)
1607 parentsWithOids++;
1608
1609 tupleDesc = RelationGetDescr(relation);
1610 constr = tupleDesc->constr;
1611
1612 /*
1613 * newattno[] will contain the child-table attribute numbers for the
1614 * attributes of this parent table. (They are not the same for
1615 * parents after the first one, nor if we have dropped columns.)
1616 */
1617 newattno = (AttrNumber *)
1618 palloc0(tupleDesc->natts * sizeof(AttrNumber));
1619
1620 for (parent_attno = 1; parent_attno <= tupleDesc->natts;
1621 parent_attno++)
1622 {
1623 Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1];
1624 char *attributeName = NameStr(attribute->attname);
1625 int exist_attno;
1626 ColumnDef *def;
1627
1628 /*
1629 * Ignore dropped columns in the parent.
1630 */
1631 if (attribute->attisdropped)
1632 continue; /* leave newattno entry as zero */
1633
1634 /*
1635 * Does it conflict with some previously inherited column?
1636 */
1637 exist_attno = findAttrByName(attributeName, inhSchema);
1638 if (exist_attno > 0)
1639 {
1640 Oid defTypeId;
1641 int32 deftypmod;
1642 Oid defCollId;
1643
1644 /*
1645 * Yes, try to merge the two column definitions. They must
1646 * have the same type, typmod, and collation.
1647 */
1648 ereport(NOTICE,
1649 (errmsg("merging multiple inherited definitions of column \"%s\"",
1650 attributeName)));
1651 def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
1652 typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
1653 if (defTypeId != attribute->atttypid ||
1654 deftypmod != attribute->atttypmod)
1655 ereport(ERROR,
1656 (errcode(ERRCODE_DATATYPE_MISMATCH),
1657 errmsg("inherited column \"%s\" has a type conflict",
1658 attributeName),
1659 errdetail("%s versus %s",
1660 format_type_with_typemod(defTypeId,
1661 deftypmod),
1662 format_type_with_typemod(attribute->atttypid,
1663 attribute->atttypmod))));
1664 defCollId = GetColumnDefCollation(NULL, def, defTypeId);
1665 if (defCollId != attribute->attcollation)
1666 ereport(ERROR,
1667 (errcode(ERRCODE_COLLATION_MISMATCH),
1668 errmsg("inherited column \"%s\" has a collation conflict",
1669 attributeName),
1670 errdetail("\"%s\" versus \"%s\"",
1671 get_collation_name(defCollId),
1672 get_collation_name(attribute->attcollation))));
1673
1674 /* Copy storage parameter */
1675 if (def->storage == 0)
1676 def->storage = attribute->attstorage;
1677 else if (def->storage != attribute->attstorage)
1678 ereport(ERROR,
1679 (errcode(ERRCODE_DATATYPE_MISMATCH),
1680 errmsg("inherited column \"%s\" has a storage parameter conflict",
1681 attributeName),
1682 errdetail("%s versus %s",
1683 storage_name(def->storage),
1684 storage_name(attribute->attstorage))));
1685
1686 def->inhcount++;
1687 /* Merge of NOT NULL constraints = OR 'em together */
1688 def->is_not_null |= attribute->attnotnull;
1689 /* Default and other constraints are handled below */
1690 newattno[parent_attno - 1] = exist_attno;
1691 }
1692 else
1693 {
1694 /*
1695 * No, create a new inherited column
1696 */
1697 def = makeNode(ColumnDef);
1698 def->colname = pstrdup(attributeName);
1699 def->typeName = makeTypeNameFromOid(attribute->atttypid,
1700 attribute->atttypmod);
1701 def->inhcount = 1;
1702 def->is_local = false;
1703 def->is_not_null = attribute->attnotnull;
1704 def->is_from_type = false;
1705 def->storage = attribute->attstorage;
1706 def->raw_default = NULL;
1707 def->cooked_default = NULL;
1708 def->collClause = NULL;
1709 def->collOid = attribute->attcollation;
1710 def->constraints = NIL;
1711 def->location = -1;
1712 inhSchema = lappend(inhSchema, def);
1713 newattno[parent_attno - 1] = ++child_attno;
1714 }
1715
1716 /*
1717 * Copy default if any
1718 */
1719 if (attribute->atthasdef)
1720 {
1721 Node *this_default = NULL;
1722 AttrDefault *attrdef;
1723 int i;
1724
1725 /* Find default in constraint structure */
1726 Assert(constr != NULL);
1727 attrdef = constr->defval;
1728 for (i = 0; i < constr->num_defval; i++)
1729 {
1730 if (attrdef[i].adnum == parent_attno)
1731 {
1732 this_default = stringToNode(attrdef[i].adbin);
1733 break;
1734 }
1735 }
1736 Assert(this_default != NULL);
1737
1738 /*
1739 * If default expr could contain any vars, we'd need to fix
1740 * 'em, but it can't; so default is ready to apply to child.
1741 *
1742 * If we already had a default from some prior parent, check
1743 * to see if they are the same. If so, no problem; if not,
1744 * mark the column as having a bogus default. Below, we will
1745 * complain if the bogus default isn't overridden by the child
1746 * schema.
1747 */
1748 Assert(def->raw_default == NULL);
1749 if (def->cooked_default == NULL)
1750 def->cooked_default = this_default;
1751 else if (!equal(def->cooked_default, this_default))
1752 {
1753 def->cooked_default = &bogus_marker;
1754 have_bogus_defaults = true;
1755 }
1756 }
1757 }
1758
1759 /*
1760 * Now copy the CHECK constraints of this parent, adjusting attnos
1761 * using the completed newattno[] map. Identically named constraints
1762 * are merged if possible, else we throw error.
1763 */
1764 if (constr && constr->num_check > 0)
1765 {
1766 ConstrCheck *check = constr->check;
1767 int i;
1768
1769 for (i = 0; i < constr->num_check; i++)
1770 {
1771 char *name = check[i].ccname;
1772 Node *expr;
1773 bool found_whole_row;
1774
1775 /* ignore if the constraint is non-inheritable */
1776 if (check[i].ccnoinherit)
1777 continue;
1778
1779 /* Adjust Vars to match new table's column numbering */
1780 expr = map_variable_attnos(stringToNode(check[i].ccbin),
1781 1, 0,
1782 newattno, tupleDesc->natts,
1783 &found_whole_row);
1784
1785 /*
1786 * For the moment we have to reject whole-row variables. We
1787 * could convert them, if we knew the new table's rowtype OID,
1788 * but that hasn't been assigned yet.
1789 */
1790 if (found_whole_row)
1791 ereport(ERROR,
1792 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1793 errmsg("cannot convert whole-row table reference"),
1794 errdetail("Constraint \"%s\" contains a whole-row reference to table \"%s\".",
1795 name,
1796 RelationGetRelationName(relation))));
1797
1798 /* check for duplicate */
1799 if (!MergeCheckConstraint(constraints, name, expr))
1800 {
1801 /* nope, this is a new one */
1802 CookedConstraint *cooked;
1803
1804 cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
1805 cooked->contype = CONSTR_CHECK;
1806 cooked->conoid = InvalidOid; /* until created */
1807 cooked->name = pstrdup(name);
1808 cooked->attnum = 0; /* not used for constraints */
1809 cooked->expr = expr;
1810 cooked->skip_validation = false;
1811 cooked->is_local = false;
1812 cooked->inhcount = 1;
1813 cooked->is_no_inherit = false;
1814 constraints = lappend(constraints, cooked);
1815 }
1816 }
1817 }
1818
1819 pfree(newattno);
1820
1821 /*
1822 * Close the parent rel, but keep our ShareUpdateExclusiveLock on it
1823 * until xact commit. That will prevent someone else from deleting or
1824 * ALTERing the parent before the child is committed.
1825 */
1826 heap_close(relation, NoLock);
1827 }
1828
1829 /*
1830 * If we had no inherited attributes, the result schema is just the
1831 * explicitly declared columns. Otherwise, we need to merge the declared
1832 * columns into the inherited schema list.
1833 */
1834 if (inhSchema != NIL)
1835 {
1836 int schema_attno = 0;
1837
1838 foreach(entry, schema)
1839 {
1840 ColumnDef *newdef = lfirst(entry);
1841 char *attributeName = newdef->colname;
1842 int exist_attno;
1843
1844 schema_attno++;
1845
1846 /*
1847 * Does it conflict with some previously inherited column?
1848 */
1849 exist_attno = findAttrByName(attributeName, inhSchema);
1850 if (exist_attno > 0)
1851 {
1852 ColumnDef *def;
1853 Oid defTypeId,
1854 newTypeId;
1855 int32 deftypmod,
1856 newtypmod;
1857 Oid defcollid,
1858 newcollid;
1859
1860 /*
1861 * Yes, try to merge the two column definitions. They must
1862 * have the same type, typmod, and collation.
1863 */
1864 if (exist_attno == schema_attno)
1865 ereport(NOTICE,
1866 (errmsg("merging column \"%s\" with inherited definition",
1867 attributeName)));
1868 else
1869 ereport(NOTICE,
1870 (errmsg("moving and merging column \"%s\" with inherited definition", attributeName),
1871 errdetail("User-specified column moved to the position of the inherited column.")));
1872 def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
1873 typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
1874 typenameTypeIdAndMod(NULL, newdef->typeName, &newTypeId, &newtypmod);
1875 if (defTypeId != newTypeId || deftypmod != newtypmod)
1876 ereport(ERROR,
1877 (errcode(ERRCODE_DATATYPE_MISMATCH),
1878 errmsg("column \"%s\" has a type conflict",
1879 attributeName),
1880 errdetail("%s versus %s",
1881 format_type_with_typemod(defTypeId,
1882 deftypmod),
1883 format_type_with_typemod(newTypeId,
1884 newtypmod))));
1885 defcollid = GetColumnDefCollation(NULL, def, defTypeId);
1886 newcollid = GetColumnDefCollation(NULL, newdef, newTypeId);
1887 if (defcollid != newcollid)
1888 ereport(ERROR,
1889 (errcode(ERRCODE_COLLATION_MISMATCH),
1890 errmsg("column \"%s\" has a collation conflict",
1891 attributeName),
1892 errdetail("\"%s\" versus \"%s\"",
1893 get_collation_name(defcollid),
1894 get_collation_name(newcollid))));
1895
1896 /* Copy storage parameter */
1897 if (def->storage == 0)
1898 def->storage = newdef->storage;
1899 else if (newdef->storage != 0 && def->storage != newdef->storage)
1900 ereport(ERROR,
1901 (errcode(ERRCODE_DATATYPE_MISMATCH),
1902 errmsg("column \"%s\" has a storage parameter conflict",
1903 attributeName),
1904 errdetail("%s versus %s",
1905 storage_name(def->storage),
1906 storage_name(newdef->storage))));
1907
1908 /* Mark the column as locally defined */
1909 def->is_local = true;
1910 /* Merge of NOT NULL constraints = OR 'em together */
1911 def->is_not_null |= newdef->is_not_null;
1912 /* If new def has a default, override previous default */
1913 if (newdef->raw_default != NULL)
1914 {
1915 def->raw_default = newdef->raw_default;
1916 def->cooked_default = newdef->cooked_default;
1917 }
1918 }
1919 else
1920 {
1921 /*
1922 * No, attach new column to result schema
1923 */
1924 inhSchema = lappend(inhSchema, newdef);
1925 }
1926 }
1927
1928 schema = inhSchema;
1929
1930 /*
1931 * Check that we haven't exceeded the legal # of columns after merging
1932 * in inherited columns.
1933 */
1934 if (list_length(schema) > MaxHeapAttributeNumber)
1935 ereport(ERROR,
1936 (errcode(ERRCODE_TOO_MANY_COLUMNS),
1937 errmsg("tables can have at most %d columns",
1938 MaxHeapAttributeNumber)));
1939 }
1940
1941 /*
1942 * If we found any conflicting parent default values, check to make sure
1943 * they were overridden by the child.
1944 */
1945 if (have_bogus_defaults)
1946 {
1947 foreach(entry, schema)
1948 {
1949 ColumnDef *def = lfirst(entry);
1950
1951 if (def->cooked_default == &bogus_marker)
1952 ereport(ERROR,
1953 (errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
1954 errmsg("column \"%s\" inherits conflicting default values",
1955 def->colname),
1956 errhint("To resolve the conflict, specify a default explicitly.")));
1957 }
1958 }
1959
1960 *supOids = parentOids;
1961 *supconstr = constraints;
1962 *supOidCount = parentsWithOids;
1963 return schema;
1964 }
1965
1966
1967 /*
1968 * MergeCheckConstraint
1969 * Try to merge an inherited CHECK constraint with previous ones
1970 *
1971 * If we inherit identically-named constraints from multiple parents, we must
1972 * merge them, or throw an error if they don't have identical definitions.
1973 *
1974 * constraints is a list of CookedConstraint structs for previous constraints.
1975 *
1976 * Returns TRUE if merged (constraint is a duplicate), or FALSE if it's
1977 * got a so-far-unique name, or throws error if conflict.
1978 */
1979 static bool
MergeCheckConstraint(List * constraints,char * name,Node * expr)1980 MergeCheckConstraint(List *constraints, char *name, Node *expr)
1981 {
1982 ListCell *lc;
1983
1984 foreach(lc, constraints)
1985 {
1986 CookedConstraint *ccon = (CookedConstraint *) lfirst(lc);
1987
1988 Assert(ccon->contype == CONSTR_CHECK);
1989
1990 /* Non-matching names never conflict */
1991 if (strcmp(ccon->name, name) != 0)
1992 continue;
1993
1994 if (equal(expr, ccon->expr))
1995 {
1996 /* OK to merge */
1997 ccon->inhcount++;
1998 return true;
1999 }
2000
2001 ereport(ERROR,
2002 (errcode(ERRCODE_DUPLICATE_OBJECT),
2003 errmsg("check constraint name \"%s\" appears multiple times but with different expressions",
2004 name)));
2005 }
2006
2007 return false;
2008 }
2009
2010
2011 /*
2012 * StoreCatalogInheritance
2013 * Updates the system catalogs with proper inheritance information.
2014 *
2015 * supers is a list of the OIDs of the new relation's direct ancestors.
2016 */
2017 static void
StoreCatalogInheritance(Oid relationId,List * supers)2018 StoreCatalogInheritance(Oid relationId, List *supers)
2019 {
2020 Relation relation;
2021 int32 seqNumber;
2022 ListCell *entry;
2023
2024 /*
2025 * sanity checks
2026 */
2027 AssertArg(OidIsValid(relationId));
2028
2029 if (supers == NIL)
2030 return;
2031
2032 /*
2033 * Store INHERITS information in pg_inherits using direct ancestors only.
2034 * Also enter dependencies on the direct ancestors, and make sure they are
2035 * marked with relhassubclass = true.
2036 *
2037 * (Once upon a time, both direct and indirect ancestors were found here
2038 * and then entered into pg_ipl. Since that catalog doesn't exist
2039 * anymore, there's no need to look for indirect ancestors.)
2040 */
2041 relation = heap_open(InheritsRelationId, RowExclusiveLock);
2042
2043 seqNumber = 1;
2044 foreach(entry, supers)
2045 {
2046 Oid parentOid = lfirst_oid(entry);
2047
2048 StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation);
2049 seqNumber++;
2050 }
2051
2052 heap_close(relation, RowExclusiveLock);
2053 }
2054
2055 /*
2056 * Make catalog entries showing relationId as being an inheritance child
2057 * of parentOid. inhRelation is the already-opened pg_inherits catalog.
2058 */
2059 static void
StoreCatalogInheritance1(Oid relationId,Oid parentOid,int32 seqNumber,Relation inhRelation)2060 StoreCatalogInheritance1(Oid relationId, Oid parentOid,
2061 int32 seqNumber, Relation inhRelation)
2062 {
2063 TupleDesc desc = RelationGetDescr(inhRelation);
2064 Datum values[Natts_pg_inherits];
2065 bool nulls[Natts_pg_inherits];
2066 ObjectAddress childobject,
2067 parentobject;
2068 HeapTuple tuple;
2069
2070 /*
2071 * Make the pg_inherits entry
2072 */
2073 values[Anum_pg_inherits_inhrelid - 1] = ObjectIdGetDatum(relationId);
2074 values[Anum_pg_inherits_inhparent - 1] = ObjectIdGetDatum(parentOid);
2075 values[Anum_pg_inherits_inhseqno - 1] = Int32GetDatum(seqNumber);
2076
2077 memset(nulls, 0, sizeof(nulls));
2078
2079 tuple = heap_form_tuple(desc, values, nulls);
2080
2081 simple_heap_insert(inhRelation, tuple);
2082
2083 CatalogUpdateIndexes(inhRelation, tuple);
2084
2085 heap_freetuple(tuple);
2086
2087 /*
2088 * Store a dependency too
2089 */
2090 parentobject.classId = RelationRelationId;
2091 parentobject.objectId = parentOid;
2092 parentobject.objectSubId = 0;
2093 childobject.classId = RelationRelationId;
2094 childobject.objectId = relationId;
2095 childobject.objectSubId = 0;
2096
2097 recordDependencyOn(&childobject, &parentobject, DEPENDENCY_NORMAL);
2098
2099 /*
2100 * Post creation hook of this inheritance. Since object_access_hook
2101 * doesn't take multiple object identifiers, we relay oid of parent
2102 * relation using auxiliary_id argument.
2103 */
2104 InvokeObjectPostAlterHookArg(InheritsRelationId,
2105 relationId, 0,
2106 parentOid, false);
2107
2108 /*
2109 * Mark the parent as having subclasses.
2110 */
2111 SetRelationHasSubclass(parentOid, true);
2112 }
2113
2114 /*
2115 * Look for an existing schema entry with the given name.
2116 *
2117 * Returns the index (starting with 1) if attribute already exists in schema,
2118 * 0 if it doesn't.
2119 */
2120 static int
findAttrByName(const char * attributeName,List * schema)2121 findAttrByName(const char *attributeName, List *schema)
2122 {
2123 ListCell *s;
2124 int i = 1;
2125
2126 foreach(s, schema)
2127 {
2128 ColumnDef *def = lfirst(s);
2129
2130 if (strcmp(attributeName, def->colname) == 0)
2131 return i;
2132
2133 i++;
2134 }
2135 return 0;
2136 }
2137
2138
2139 /*
2140 * SetRelationHasSubclass
2141 * Set the value of the relation's relhassubclass field in pg_class.
2142 *
2143 * NOTE: caller must be holding an appropriate lock on the relation.
2144 * ShareUpdateExclusiveLock is sufficient.
2145 *
2146 * NOTE: an important side-effect of this operation is that an SI invalidation
2147 * message is sent out to all backends --- including me --- causing plans
2148 * referencing the relation to be rebuilt with the new list of children.
2149 * This must happen even if we find that no change is needed in the pg_class
2150 * row.
2151 */
2152 void
SetRelationHasSubclass(Oid relationId,bool relhassubclass)2153 SetRelationHasSubclass(Oid relationId, bool relhassubclass)
2154 {
2155 Relation relationRelation;
2156 HeapTuple tuple;
2157 Form_pg_class classtuple;
2158
2159 /*
2160 * Fetch a modifiable copy of the tuple, modify it, update pg_class.
2161 */
2162 relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
2163 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
2164 if (!HeapTupleIsValid(tuple))
2165 elog(ERROR, "cache lookup failed for relation %u", relationId);
2166 classtuple = (Form_pg_class) GETSTRUCT(tuple);
2167
2168 if (classtuple->relhassubclass != relhassubclass)
2169 {
2170 classtuple->relhassubclass = relhassubclass;
2171 simple_heap_update(relationRelation, &tuple->t_self, tuple);
2172
2173 /* keep the catalog indexes up to date */
2174 CatalogUpdateIndexes(relationRelation, tuple);
2175 }
2176 else
2177 {
2178 /* no need to change tuple, but force relcache rebuild anyway */
2179 CacheInvalidateRelcacheByTuple(tuple);
2180 }
2181
2182 heap_freetuple(tuple);
2183 heap_close(relationRelation, RowExclusiveLock);
2184 }
2185
2186 /*
2187 * renameatt_check - basic sanity checks before attribute rename
2188 */
2189 static void
renameatt_check(Oid myrelid,Form_pg_class classform,bool recursing)2190 renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing)
2191 {
2192 char relkind = classform->relkind;
2193
2194 if (classform->reloftype && !recursing)
2195 ereport(ERROR,
2196 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
2197 errmsg("cannot rename column of typed table")));
2198
2199 /*
2200 * Renaming the columns of sequences or toast tables doesn't actually
2201 * break anything from the system's point of view, since internal
2202 * references are by attnum. But it doesn't seem right to allow users to
2203 * change names that are hardcoded into the system, hence the following
2204 * restriction.
2205 */
2206 if (relkind != RELKIND_RELATION &&
2207 relkind != RELKIND_VIEW &&
2208 relkind != RELKIND_MATVIEW &&
2209 relkind != RELKIND_COMPOSITE_TYPE &&
2210 relkind != RELKIND_INDEX &&
2211 relkind != RELKIND_FOREIGN_TABLE)
2212 ereport(ERROR,
2213 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
2214 errmsg("\"%s\" is not a table, view, materialized view, composite type, index, or foreign table",
2215 NameStr(classform->relname))));
2216
2217 /*
2218 * permissions checking. only the owner of a class can change its schema.
2219 */
2220 if (!pg_class_ownercheck(myrelid, GetUserId()))
2221 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
2222 NameStr(classform->relname));
2223 if (!allowSystemTableMods && IsSystemClass(myrelid, classform))
2224 ereport(ERROR,
2225 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
2226 errmsg("permission denied: \"%s\" is a system catalog",
2227 NameStr(classform->relname))));
2228 }
2229
2230 /*
2231 * renameatt_internal - workhorse for renameatt
2232 *
2233 * Return value is the attribute number in the 'myrelid' relation.
2234 */
2235 static AttrNumber
renameatt_internal(Oid myrelid,const char * oldattname,const char * newattname,bool recurse,bool recursing,int expected_parents,DropBehavior behavior)2236 renameatt_internal(Oid myrelid,
2237 const char *oldattname,
2238 const char *newattname,
2239 bool recurse,
2240 bool recursing,
2241 int expected_parents,
2242 DropBehavior behavior)
2243 {
2244 Relation targetrelation;
2245 Relation attrelation;
2246 HeapTuple atttup;
2247 Form_pg_attribute attform;
2248 AttrNumber attnum;
2249
2250 /*
2251 * Grab an exclusive lock on the target table, which we will NOT release
2252 * until end of transaction.
2253 */
2254 targetrelation = relation_open(myrelid, AccessExclusiveLock);
2255 renameatt_check(myrelid, RelationGetForm(targetrelation), recursing);
2256
2257 /*
2258 * if the 'recurse' flag is set then we are supposed to rename this
2259 * attribute in all classes that inherit from 'relname' (as well as in
2260 * 'relname').
2261 *
2262 * any permissions or problems with duplicate attributes will cause the
2263 * whole transaction to abort, which is what we want -- all or nothing.
2264 */
2265 if (recurse)
2266 {
2267 List *child_oids,
2268 *child_numparents;
2269 ListCell *lo,
2270 *li;
2271
2272 /*
2273 * we need the number of parents for each child so that the recursive
2274 * calls to renameatt() can determine whether there are any parents
2275 * outside the inheritance hierarchy being processed.
2276 */
2277 child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
2278 &child_numparents);
2279
2280 /*
2281 * find_all_inheritors does the recursive search of the inheritance
2282 * hierarchy, so all we have to do is process all of the relids in the
2283 * list that it returns.
2284 */
2285 forboth(lo, child_oids, li, child_numparents)
2286 {
2287 Oid childrelid = lfirst_oid(lo);
2288 int numparents = lfirst_int(li);
2289
2290 if (childrelid == myrelid)
2291 continue;
2292 /* note we need not recurse again */
2293 renameatt_internal(childrelid, oldattname, newattname, false, true, numparents, behavior);
2294 }
2295 }
2296 else
2297 {
2298 /*
2299 * If we are told not to recurse, there had better not be any child
2300 * tables; else the rename would put them out of step.
2301 *
2302 * expected_parents will only be 0 if we are not already recursing.
2303 */
2304 if (expected_parents == 0 &&
2305 find_inheritance_children(myrelid, NoLock) != NIL)
2306 ereport(ERROR,
2307 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2308 errmsg("inherited column \"%s\" must be renamed in child tables too",
2309 oldattname)));
2310 }
2311
2312 /* rename attributes in typed tables of composite type */
2313 if (targetrelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
2314 {
2315 List *child_oids;
2316 ListCell *lo;
2317
2318 child_oids = find_typed_table_dependencies(targetrelation->rd_rel->reltype,
2319 RelationGetRelationName(targetrelation),
2320 behavior);
2321
2322 foreach(lo, child_oids)
2323 renameatt_internal(lfirst_oid(lo), oldattname, newattname, true, true, 0, behavior);
2324 }
2325
2326 attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
2327
2328 atttup = SearchSysCacheCopyAttName(myrelid, oldattname);
2329 if (!HeapTupleIsValid(atttup))
2330 ereport(ERROR,
2331 (errcode(ERRCODE_UNDEFINED_COLUMN),
2332 errmsg("column \"%s\" does not exist",
2333 oldattname)));
2334 attform = (Form_pg_attribute) GETSTRUCT(atttup);
2335
2336 attnum = attform->attnum;
2337 if (attnum <= 0)
2338 ereport(ERROR,
2339 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2340 errmsg("cannot rename system column \"%s\"",
2341 oldattname)));
2342
2343 /*
2344 * if the attribute is inherited, forbid the renaming. if this is a
2345 * top-level call to renameatt(), then expected_parents will be 0, so the
2346 * effect of this code will be to prohibit the renaming if the attribute
2347 * is inherited at all. if this is a recursive call to renameatt(),
2348 * expected_parents will be the number of parents the current relation has
2349 * within the inheritance hierarchy being processed, so we'll prohibit the
2350 * renaming only if there are additional parents from elsewhere.
2351 */
2352 if (attform->attinhcount > expected_parents)
2353 ereport(ERROR,
2354 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2355 errmsg("cannot rename inherited column \"%s\"",
2356 oldattname)));
2357
2358 /* new name should not already exist */
2359 (void) check_for_column_name_collision(targetrelation, newattname, false);
2360
2361 /* apply the update */
2362 namestrcpy(&(attform->attname), newattname);
2363
2364 simple_heap_update(attrelation, &atttup->t_self, atttup);
2365
2366 /* keep system catalog indexes current */
2367 CatalogUpdateIndexes(attrelation, atttup);
2368
2369 InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum);
2370
2371 heap_freetuple(atttup);
2372
2373 heap_close(attrelation, RowExclusiveLock);
2374
2375 relation_close(targetrelation, NoLock); /* close rel but keep lock */
2376
2377 return attnum;
2378 }
2379
2380 /*
2381 * Perform permissions and integrity checks before acquiring a relation lock.
2382 */
2383 static void
RangeVarCallbackForRenameAttribute(const RangeVar * rv,Oid relid,Oid oldrelid,void * arg)2384 RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid,
2385 void *arg)
2386 {
2387 HeapTuple tuple;
2388 Form_pg_class form;
2389
2390 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
2391 if (!HeapTupleIsValid(tuple))
2392 return; /* concurrently dropped */
2393 form = (Form_pg_class) GETSTRUCT(tuple);
2394 renameatt_check(relid, form, false);
2395 ReleaseSysCache(tuple);
2396 }
2397
2398 /*
2399 * renameatt - changes the name of an attribute in a relation
2400 *
2401 * The returned ObjectAddress is that of the renamed column.
2402 */
2403 ObjectAddress
renameatt(RenameStmt * stmt)2404 renameatt(RenameStmt *stmt)
2405 {
2406 Oid relid;
2407 AttrNumber attnum;
2408 ObjectAddress address;
2409
2410 /* lock level taken here should match renameatt_internal */
2411 relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
2412 stmt->missing_ok, false,
2413 RangeVarCallbackForRenameAttribute,
2414 NULL);
2415
2416 if (!OidIsValid(relid))
2417 {
2418 ereport(NOTICE,
2419 (errmsg("relation \"%s\" does not exist, skipping",
2420 stmt->relation->relname)));
2421 return InvalidObjectAddress;
2422 }
2423
2424 attnum =
2425 renameatt_internal(relid,
2426 stmt->subname, /* old att name */
2427 stmt->newname, /* new att name */
2428 interpretInhOption(stmt->relation->inhOpt), /* recursive? */
2429 false, /* recursing? */
2430 0, /* expected inhcount */
2431 stmt->behavior);
2432
2433 ObjectAddressSubSet(address, RelationRelationId, relid, attnum);
2434
2435 return address;
2436 }
2437
2438 /*
2439 * same logic as renameatt_internal
2440 */
2441 static ObjectAddress
rename_constraint_internal(Oid myrelid,Oid mytypid,const char * oldconname,const char * newconname,bool recurse,bool recursing,int expected_parents)2442 rename_constraint_internal(Oid myrelid,
2443 Oid mytypid,
2444 const char *oldconname,
2445 const char *newconname,
2446 bool recurse,
2447 bool recursing,
2448 int expected_parents)
2449 {
2450 Relation targetrelation = NULL;
2451 Oid constraintOid;
2452 HeapTuple tuple;
2453 Form_pg_constraint con;
2454 ObjectAddress address;
2455
2456 AssertArg(!myrelid || !mytypid);
2457
2458 if (mytypid)
2459 {
2460 constraintOid = get_domain_constraint_oid(mytypid, oldconname, false);
2461 }
2462 else
2463 {
2464 targetrelation = relation_open(myrelid, AccessExclusiveLock);
2465
2466 /*
2467 * don't tell it whether we're recursing; we allow changing typed
2468 * tables here
2469 */
2470 renameatt_check(myrelid, RelationGetForm(targetrelation), false);
2471
2472 constraintOid = get_relation_constraint_oid(myrelid, oldconname, false);
2473 }
2474
2475 tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
2476 if (!HeapTupleIsValid(tuple))
2477 elog(ERROR, "cache lookup failed for constraint %u",
2478 constraintOid);
2479 con = (Form_pg_constraint) GETSTRUCT(tuple);
2480
2481 if (myrelid && con->contype == CONSTRAINT_CHECK && !con->connoinherit)
2482 {
2483 if (recurse)
2484 {
2485 List *child_oids,
2486 *child_numparents;
2487 ListCell *lo,
2488 *li;
2489
2490 child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
2491 &child_numparents);
2492
2493 forboth(lo, child_oids, li, child_numparents)
2494 {
2495 Oid childrelid = lfirst_oid(lo);
2496 int numparents = lfirst_int(li);
2497
2498 if (childrelid == myrelid)
2499 continue;
2500
2501 rename_constraint_internal(childrelid, InvalidOid, oldconname, newconname, false, true, numparents);
2502 }
2503 }
2504 else
2505 {
2506 if (expected_parents == 0 &&
2507 find_inheritance_children(myrelid, NoLock) != NIL)
2508 ereport(ERROR,
2509 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2510 errmsg("inherited constraint \"%s\" must be renamed in child tables too",
2511 oldconname)));
2512 }
2513
2514 if (con->coninhcount > expected_parents)
2515 ereport(ERROR,
2516 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
2517 errmsg("cannot rename inherited constraint \"%s\"",
2518 oldconname)));
2519 }
2520
2521 if (con->conindid
2522 && (con->contype == CONSTRAINT_PRIMARY
2523 || con->contype == CONSTRAINT_UNIQUE
2524 || con->contype == CONSTRAINT_EXCLUSION))
2525 /* rename the index; this renames the constraint as well */
2526 RenameRelationInternal(con->conindid, newconname, false);
2527 else
2528 RenameConstraintById(constraintOid, newconname);
2529
2530 ObjectAddressSet(address, ConstraintRelationId, constraintOid);
2531
2532 ReleaseSysCache(tuple);
2533
2534 if (targetrelation)
2535 {
2536 /*
2537 * Invalidate relcache so as others can see the new constraint name.
2538 */
2539 CacheInvalidateRelcache(targetrelation);
2540
2541 relation_close(targetrelation, NoLock); /* close rel but keep lock */
2542 }
2543
2544 return address;
2545 }
2546
2547 ObjectAddress
RenameConstraint(RenameStmt * stmt)2548 RenameConstraint(RenameStmt *stmt)
2549 {
2550 Oid relid = InvalidOid;
2551 Oid typid = InvalidOid;
2552
2553 if (stmt->renameType == OBJECT_DOMCONSTRAINT)
2554 {
2555 Relation rel;
2556 HeapTuple tup;
2557
2558 typid = typenameTypeId(NULL, makeTypeNameFromNameList(stmt->object));
2559 rel = heap_open(TypeRelationId, RowExclusiveLock);
2560 tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
2561 if (!HeapTupleIsValid(tup))
2562 elog(ERROR, "cache lookup failed for type %u", typid);
2563 checkDomainOwner(tup);
2564 ReleaseSysCache(tup);
2565 heap_close(rel, NoLock);
2566 }
2567 else
2568 {
2569 /* lock level taken here should match rename_constraint_internal */
2570 relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
2571 stmt->missing_ok, false,
2572 RangeVarCallbackForRenameAttribute,
2573 NULL);
2574 if (!OidIsValid(relid))
2575 {
2576 ereport(NOTICE,
2577 (errmsg("relation \"%s\" does not exist, skipping",
2578 stmt->relation->relname)));
2579 return InvalidObjectAddress;
2580 }
2581 }
2582
2583 return
2584 rename_constraint_internal(relid, typid,
2585 stmt->subname,
2586 stmt->newname,
2587 stmt->relation ? interpretInhOption(stmt->relation->inhOpt) : false, /* recursive? */
2588 false, /* recursing? */
2589 0 /* expected inhcount */ );
2590
2591 }
2592
2593 /*
2594 * Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE
2595 * RENAME
2596 */
2597 ObjectAddress
RenameRelation(RenameStmt * stmt)2598 RenameRelation(RenameStmt *stmt)
2599 {
2600 Oid relid;
2601 ObjectAddress address;
2602
2603 /*
2604 * Grab an exclusive lock on the target table, index, sequence, view,
2605 * materialized view, or foreign table, which we will NOT release until
2606 * end of transaction.
2607 *
2608 * Lock level used here should match RenameRelationInternal, to avoid lock
2609 * escalation.
2610 */
2611 relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
2612 stmt->missing_ok, false,
2613 RangeVarCallbackForAlterRelation,
2614 (void *) stmt);
2615
2616 if (!OidIsValid(relid))
2617 {
2618 ereport(NOTICE,
2619 (errmsg("relation \"%s\" does not exist, skipping",
2620 stmt->relation->relname)));
2621 return InvalidObjectAddress;
2622 }
2623
2624 /* Do the work */
2625 RenameRelationInternal(relid, stmt->newname, false);
2626
2627 ObjectAddressSet(address, RelationRelationId, relid);
2628
2629 return address;
2630 }
2631
2632 /*
2633 * RenameRelationInternal - change the name of a relation
2634 *
2635 * XXX - When renaming sequences, we don't bother to modify the
2636 * sequence name that is stored within the sequence itself
2637 * (this would cause problems with MVCC). In the future,
2638 * the sequence name should probably be removed from the
2639 * sequence, AFAIK there's no need for it to be there.
2640 */
2641 void
RenameRelationInternal(Oid myrelid,const char * newrelname,bool is_internal)2642 RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal)
2643 {
2644 Relation targetrelation;
2645 Relation relrelation; /* for RELATION relation */
2646 HeapTuple reltup;
2647 Form_pg_class relform;
2648 Oid namespaceId;
2649
2650 /*
2651 * Grab an exclusive lock on the target table, index, sequence, view,
2652 * materialized view, or foreign table, which we will NOT release until
2653 * end of transaction.
2654 */
2655 targetrelation = relation_open(myrelid, AccessExclusiveLock);
2656 namespaceId = RelationGetNamespace(targetrelation);
2657
2658 /*
2659 * Find relation's pg_class tuple, and make sure newrelname isn't in use.
2660 */
2661 relrelation = heap_open(RelationRelationId, RowExclusiveLock);
2662
2663 reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
2664 if (!HeapTupleIsValid(reltup)) /* shouldn't happen */
2665 elog(ERROR, "cache lookup failed for relation %u", myrelid);
2666 relform = (Form_pg_class) GETSTRUCT(reltup);
2667
2668 if (get_relname_relid(newrelname, namespaceId) != InvalidOid)
2669 ereport(ERROR,
2670 (errcode(ERRCODE_DUPLICATE_TABLE),
2671 errmsg("relation \"%s\" already exists",
2672 newrelname)));
2673
2674 /*
2675 * Update pg_class tuple with new relname. (Scribbling on reltup is OK
2676 * because it's a copy...)
2677 */
2678 namestrcpy(&(relform->relname), newrelname);
2679
2680 simple_heap_update(relrelation, &reltup->t_self, reltup);
2681
2682 /* keep the system catalog indexes current */
2683 CatalogUpdateIndexes(relrelation, reltup);
2684
2685 InvokeObjectPostAlterHookArg(RelationRelationId, myrelid, 0,
2686 InvalidOid, is_internal);
2687
2688 heap_freetuple(reltup);
2689 heap_close(relrelation, RowExclusiveLock);
2690
2691 /*
2692 * Also rename the associated type, if any.
2693 */
2694 if (OidIsValid(targetrelation->rd_rel->reltype))
2695 RenameTypeInternal(targetrelation->rd_rel->reltype,
2696 newrelname, namespaceId);
2697
2698 /*
2699 * Also rename the associated constraint, if any.
2700 */
2701 if (targetrelation->rd_rel->relkind == RELKIND_INDEX)
2702 {
2703 Oid constraintId = get_index_constraint(myrelid);
2704
2705 if (OidIsValid(constraintId))
2706 RenameConstraintById(constraintId, newrelname);
2707 }
2708
2709 /*
2710 * Close rel, but keep exclusive lock!
2711 */
2712 relation_close(targetrelation, NoLock);
2713 }
2714
2715 /*
2716 * Disallow ALTER TABLE (and similar commands) when the current backend has
2717 * any open reference to the target table besides the one just acquired by
2718 * the calling command; this implies there's an open cursor or active plan.
2719 * We need this check because our lock doesn't protect us against stomping
2720 * on our own foot, only other people's feet!
2721 *
2722 * For ALTER TABLE, the only case known to cause serious trouble is ALTER
2723 * COLUMN TYPE, and some changes are obviously pretty benign, so this could
2724 * possibly be relaxed to only error out for certain types of alterations.
2725 * But the use-case for allowing any of these things is not obvious, so we
2726 * won't work hard at it for now.
2727 *
2728 * We also reject these commands if there are any pending AFTER trigger events
2729 * for the rel. This is certainly necessary for the rewriting variants of
2730 * ALTER TABLE, because they don't preserve tuple TIDs and so the pending
2731 * events would try to fetch the wrong tuples. It might be overly cautious
2732 * in other cases, but again it seems better to err on the side of paranoia.
2733 *
2734 * REINDEX calls this with "rel" referencing the index to be rebuilt; here
2735 * we are worried about active indexscans on the index. The trigger-event
2736 * check can be skipped, since we are doing no damage to the parent table.
2737 *
2738 * The statement name (eg, "ALTER TABLE") is passed for use in error messages.
2739 */
2740 void
CheckTableNotInUse(Relation rel,const char * stmt)2741 CheckTableNotInUse(Relation rel, const char *stmt)
2742 {
2743 int expected_refcnt;
2744
2745 expected_refcnt = rel->rd_isnailed ? 2 : 1;
2746 if (rel->rd_refcnt != expected_refcnt)
2747 ereport(ERROR,
2748 (errcode(ERRCODE_OBJECT_IN_USE),
2749 /* translator: first %s is a SQL command, eg ALTER TABLE */
2750 errmsg("cannot %s \"%s\" because "
2751 "it is being used by active queries in this session",
2752 stmt, RelationGetRelationName(rel))));
2753
2754 if (rel->rd_rel->relkind != RELKIND_INDEX &&
2755 AfterTriggerPendingOnRel(RelationGetRelid(rel)))
2756 ereport(ERROR,
2757 (errcode(ERRCODE_OBJECT_IN_USE),
2758 /* translator: first %s is a SQL command, eg ALTER TABLE */
2759 errmsg("cannot %s \"%s\" because "
2760 "it has pending trigger events",
2761 stmt, RelationGetRelationName(rel))));
2762 }
2763
2764 /*
2765 * AlterTableLookupRelation
2766 * Look up, and lock, the OID for the relation named by an alter table
2767 * statement.
2768 */
2769 Oid
AlterTableLookupRelation(AlterTableStmt * stmt,LOCKMODE lockmode)2770 AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode)
2771 {
2772 return RangeVarGetRelidExtended(stmt->relation, lockmode, stmt->missing_ok, false,
2773 RangeVarCallbackForAlterRelation,
2774 (void *) stmt);
2775 }
2776
2777 /*
2778 * AlterTable
2779 * Execute ALTER TABLE, which can be a list of subcommands
2780 *
2781 * ALTER TABLE is performed in three phases:
2782 * 1. Examine subcommands and perform pre-transformation checking.
2783 * 2. Update system catalogs.
2784 * 3. Scan table(s) to check new constraints, and optionally recopy
2785 * the data into new table(s).
2786 * Phase 3 is not performed unless one or more of the subcommands requires
2787 * it. The intention of this design is to allow multiple independent
2788 * updates of the table schema to be performed with only one pass over the
2789 * data.
2790 *
2791 * ATPrepCmd performs phase 1. A "work queue" entry is created for
2792 * each table to be affected (there may be multiple affected tables if the
2793 * commands traverse a table inheritance hierarchy). Also we do preliminary
2794 * validation of the subcommands, including parse transformation of those
2795 * expressions that need to be evaluated with respect to the old table
2796 * schema.
2797 *
2798 * ATRewriteCatalogs performs phase 2 for each affected table. (Note that
2799 * phases 2 and 3 normally do no explicit recursion, since phase 1 already
2800 * did it --- although some subcommands have to recurse in phase 2 instead.)
2801 * Certain subcommands need to be performed before others to avoid
2802 * unnecessary conflicts; for example, DROP COLUMN should come before
2803 * ADD COLUMN. Therefore phase 1 divides the subcommands into multiple
2804 * lists, one for each logical "pass" of phase 2.
2805 *
2806 * ATRewriteTables performs phase 3 for those tables that need it.
2807 *
2808 * Thanks to the magic of MVCC, an error anywhere along the way rolls back
2809 * the whole operation; we don't have to do anything special to clean up.
2810 *
2811 * The caller must lock the relation, with an appropriate lock level
2812 * for the subcommands requested, using AlterTableGetLockLevel(stmt->cmds)
2813 * or higher. We pass the lock level down
2814 * so that we can apply it recursively to inherited tables. Note that the
2815 * lock level we want as we recurse might well be higher than required for
2816 * that specific subcommand. So we pass down the overall lock requirement,
2817 * rather than reassess it at lower levels.
2818 */
2819 void
AlterTable(Oid relid,LOCKMODE lockmode,AlterTableStmt * stmt)2820 AlterTable(Oid relid, LOCKMODE lockmode, AlterTableStmt *stmt)
2821 {
2822 Relation rel;
2823
2824 /* Caller is required to provide an adequate lock. */
2825 rel = relation_open(relid, NoLock);
2826
2827 CheckTableNotInUse(rel, "ALTER TABLE");
2828
2829 ATController(stmt,
2830 rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt),
2831 lockmode);
2832 }
2833
2834 /*
2835 * AlterTableInternal
2836 *
2837 * ALTER TABLE with target specified by OID
2838 *
2839 * We do not reject if the relation is already open, because it's quite
2840 * likely that one or more layers of caller have it open. That means it
2841 * is unsafe to use this entry point for alterations that could break
2842 * existing query plans. On the assumption it's not used for such, we
2843 * don't have to reject pending AFTER triggers, either.
2844 */
2845 void
AlterTableInternal(Oid relid,List * cmds,bool recurse)2846 AlterTableInternal(Oid relid, List *cmds, bool recurse)
2847 {
2848 Relation rel;
2849 LOCKMODE lockmode = AlterTableGetLockLevel(cmds);
2850
2851 rel = relation_open(relid, lockmode);
2852
2853 EventTriggerAlterTableRelid(relid);
2854
2855 ATController(NULL, rel, cmds, recurse, lockmode);
2856 }
2857
2858 /*
2859 * AlterTableGetLockLevel
2860 *
2861 * Sets the overall lock level required for the supplied list of subcommands.
2862 * Policy for doing this set according to needs of AlterTable(), see
2863 * comments there for overall explanation.
2864 *
2865 * Function is called before and after parsing, so it must give same
2866 * answer each time it is called. Some subcommands are transformed
2867 * into other subcommand types, so the transform must never be made to a
2868 * lower lock level than previously assigned. All transforms are noted below.
2869 *
2870 * Since this is called before we lock the table we cannot use table metadata
2871 * to influence the type of lock we acquire.
2872 *
2873 * There should be no lockmodes hardcoded into the subcommand functions. All
2874 * lockmode decisions for ALTER TABLE are made here only. The one exception is
2875 * ALTER TABLE RENAME which is treated as a different statement type T_RenameStmt
2876 * and does not travel through this section of code and cannot be combined with
2877 * any of the subcommands given here.
2878 *
2879 * Note that Hot Standby only knows about AccessExclusiveLocks on the master
2880 * so any changes that might affect SELECTs running on standbys need to use
2881 * AccessExclusiveLocks even if you think a lesser lock would do, unless you
2882 * have a solution for that also.
2883 *
2884 * Also note that pg_dump uses only an AccessShareLock, meaning that anything
2885 * that takes a lock less than AccessExclusiveLock can change object definitions
2886 * while pg_dump is running. Be careful to check that the appropriate data is
2887 * derived by pg_dump using an MVCC snapshot, rather than syscache lookups,
2888 * otherwise we might end up with an inconsistent dump that can't restore.
2889 */
2890 LOCKMODE
AlterTableGetLockLevel(List * cmds)2891 AlterTableGetLockLevel(List *cmds)
2892 {
2893 /*
2894 * This only works if we read catalog tables using MVCC snapshots.
2895 */
2896 ListCell *lcmd;
2897 LOCKMODE lockmode = ShareUpdateExclusiveLock;
2898
2899 foreach(lcmd, cmds)
2900 {
2901 AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
2902 LOCKMODE cmd_lockmode = AccessExclusiveLock; /* default for compiler */
2903
2904 switch (cmd->subtype)
2905 {
2906 /*
2907 * These subcommands rewrite the heap, so require full locks.
2908 */
2909 case AT_AddColumn: /* may rewrite heap, in some cases and visible
2910 * to SELECT */
2911 case AT_SetTableSpace: /* must rewrite heap */
2912 case AT_AlterColumnType: /* must rewrite heap */
2913 case AT_AddOids: /* must rewrite heap */
2914 cmd_lockmode = AccessExclusiveLock;
2915 break;
2916
2917 /*
2918 * These subcommands may require addition of toast tables. If
2919 * we add a toast table to a table currently being scanned, we
2920 * might miss data added to the new toast table by concurrent
2921 * insert transactions.
2922 */
2923 case AT_SetStorage:/* may add toast tables, see
2924 * ATRewriteCatalogs() */
2925 cmd_lockmode = AccessExclusiveLock;
2926 break;
2927
2928 /*
2929 * Removing constraints can affect SELECTs that have been
2930 * optimised assuming the constraint holds true.
2931 */
2932 case AT_DropConstraint: /* as DROP INDEX */
2933 case AT_DropNotNull: /* may change some SQL plans */
2934 cmd_lockmode = AccessExclusiveLock;
2935 break;
2936
2937 /*
2938 * Subcommands that may be visible to concurrent SELECTs
2939 */
2940 case AT_DropColumn: /* change visible to SELECT */
2941 case AT_AddColumnToView: /* CREATE VIEW */
2942 case AT_DropOids: /* calls AT_DropColumn */
2943 case AT_EnableAlwaysRule: /* may change SELECT rules */
2944 case AT_EnableReplicaRule: /* may change SELECT rules */
2945 case AT_EnableRule: /* may change SELECT rules */
2946 case AT_DisableRule: /* may change SELECT rules */
2947 cmd_lockmode = AccessExclusiveLock;
2948 break;
2949
2950 /*
2951 * Changing owner may remove implicit SELECT privileges
2952 */
2953 case AT_ChangeOwner: /* change visible to SELECT */
2954 cmd_lockmode = AccessExclusiveLock;
2955 break;
2956
2957 /*
2958 * Changing foreign table options may affect optimisation.
2959 */
2960 case AT_GenericOptions:
2961 case AT_AlterColumnGenericOptions:
2962 cmd_lockmode = AccessExclusiveLock;
2963 break;
2964
2965 /*
2966 * These subcommands affect write operations only.
2967 */
2968 case AT_EnableTrig:
2969 case AT_EnableAlwaysTrig:
2970 case AT_EnableReplicaTrig:
2971 case AT_EnableTrigAll:
2972 case AT_EnableTrigUser:
2973 case AT_DisableTrig:
2974 case AT_DisableTrigAll:
2975 case AT_DisableTrigUser:
2976 cmd_lockmode = ShareRowExclusiveLock;
2977 break;
2978
2979 /*
2980 * These subcommands affect write operations only. XXX
2981 * Theoretically, these could be ShareRowExclusiveLock.
2982 */
2983 case AT_ColumnDefault:
2984 case AT_AlterConstraint:
2985 case AT_AddIndex: /* from ADD CONSTRAINT */
2986 case AT_AddIndexConstraint:
2987 case AT_ReplicaIdentity:
2988 case AT_SetNotNull:
2989 case AT_EnableRowSecurity:
2990 case AT_DisableRowSecurity:
2991 case AT_ForceRowSecurity:
2992 case AT_NoForceRowSecurity:
2993 cmd_lockmode = AccessExclusiveLock;
2994 break;
2995
2996 case AT_AddConstraint:
2997 case AT_ProcessedConstraint: /* becomes AT_AddConstraint */
2998 case AT_AddConstraintRecurse: /* becomes AT_AddConstraint */
2999 case AT_ReAddConstraint: /* becomes AT_AddConstraint */
3000 if (IsA(cmd->def, Constraint))
3001 {
3002 Constraint *con = (Constraint *) cmd->def;
3003
3004 switch (con->contype)
3005 {
3006 case CONSTR_EXCLUSION:
3007 case CONSTR_PRIMARY:
3008 case CONSTR_UNIQUE:
3009
3010 /*
3011 * Cases essentially the same as CREATE INDEX. We
3012 * could reduce the lock strength to ShareLock if
3013 * we can work out how to allow concurrent catalog
3014 * updates. XXX Might be set down to
3015 * ShareRowExclusiveLock but requires further
3016 * analysis.
3017 */
3018 cmd_lockmode = AccessExclusiveLock;
3019 break;
3020 case CONSTR_FOREIGN:
3021
3022 /*
3023 * We add triggers to both tables when we add a
3024 * Foreign Key, so the lock level must be at least
3025 * as strong as CREATE TRIGGER.
3026 */
3027 cmd_lockmode = ShareRowExclusiveLock;
3028 break;
3029
3030 default:
3031 cmd_lockmode = AccessExclusiveLock;
3032 }
3033 }
3034 break;
3035
3036 /*
3037 * These subcommands affect inheritance behaviour. Queries
3038 * started before us will continue to see the old inheritance
3039 * behaviour, while queries started after we commit will see
3040 * new behaviour. No need to prevent reads or writes to the
3041 * subtable while we hook it up though. Changing the TupDesc
3042 * may be a problem, so keep highest lock.
3043 */
3044 case AT_AddInherit:
3045 case AT_DropInherit:
3046 cmd_lockmode = AccessExclusiveLock;
3047 break;
3048
3049 /*
3050 * These subcommands affect implicit row type conversion. They
3051 * have affects similar to CREATE/DROP CAST on queries. don't
3052 * provide for invalidating parse trees as a result of such
3053 * changes, so we keep these at AccessExclusiveLock.
3054 */
3055 case AT_AddOf:
3056 case AT_DropOf:
3057 cmd_lockmode = AccessExclusiveLock;
3058 break;
3059
3060 /*
3061 * Only used by CREATE OR REPLACE VIEW which must conflict
3062 * with an SELECTs currently using the view.
3063 */
3064 case AT_ReplaceRelOptions:
3065 cmd_lockmode = AccessExclusiveLock;
3066 break;
3067
3068 /*
3069 * These subcommands affect general strategies for performance
3070 * and maintenance, though don't change the semantic results
3071 * from normal data reads and writes. Delaying an ALTER TABLE
3072 * behind currently active writes only delays the point where
3073 * the new strategy begins to take effect, so there is no
3074 * benefit in waiting. In this case the minimum restriction
3075 * applies: we don't currently allow concurrent catalog
3076 * updates.
3077 */
3078 case AT_SetStatistics: /* Uses MVCC in getTableAttrs() */
3079 case AT_ClusterOn: /* Uses MVCC in getIndexes() */
3080 case AT_DropCluster: /* Uses MVCC in getIndexes() */
3081 case AT_SetOptions: /* Uses MVCC in getTableAttrs() */
3082 case AT_ResetOptions: /* Uses MVCC in getTableAttrs() */
3083 cmd_lockmode = ShareUpdateExclusiveLock;
3084 break;
3085
3086 case AT_SetLogged:
3087 case AT_SetUnLogged:
3088 cmd_lockmode = AccessExclusiveLock;
3089 break;
3090
3091 case AT_ValidateConstraint: /* Uses MVCC in
3092 * getConstraints() */
3093 cmd_lockmode = ShareUpdateExclusiveLock;
3094 break;
3095
3096 /*
3097 * Rel options are more complex than first appears. Options
3098 * are set here for tables, views and indexes; for historical
3099 * reasons these can all be used with ALTER TABLE, so we can't
3100 * decide between them using the basic grammar.
3101 */
3102 case AT_SetRelOptions: /* Uses MVCC in getIndexes() and
3103 * getTables() */
3104 case AT_ResetRelOptions: /* Uses MVCC in getIndexes() and
3105 * getTables() */
3106 cmd_lockmode = AlterTableGetRelOptionsLockLevel((List *) cmd->def);
3107 break;
3108
3109 default: /* oops */
3110 elog(ERROR, "unrecognized alter table type: %d",
3111 (int) cmd->subtype);
3112 break;
3113 }
3114
3115 /*
3116 * Take the greatest lockmode from any subcommand
3117 */
3118 if (cmd_lockmode > lockmode)
3119 lockmode = cmd_lockmode;
3120 }
3121
3122 return lockmode;
3123 }
3124
3125 /*
3126 * ATController provides top level control over the phases.
3127 *
3128 * parsetree is passed in to allow it to be passed to event triggers
3129 * when requested.
3130 */
3131 static void
ATController(AlterTableStmt * parsetree,Relation rel,List * cmds,bool recurse,LOCKMODE lockmode)3132 ATController(AlterTableStmt *parsetree,
3133 Relation rel, List *cmds, bool recurse, LOCKMODE lockmode)
3134 {
3135 List *wqueue = NIL;
3136 ListCell *lcmd;
3137
3138 /* Phase 1: preliminary examination of commands, create work queue */
3139 foreach(lcmd, cmds)
3140 {
3141 AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
3142
3143 ATPrepCmd(&wqueue, rel, cmd, recurse, false, lockmode);
3144 }
3145
3146 /* Close the relation, but keep lock until commit */
3147 relation_close(rel, NoLock);
3148
3149 /* Phase 2: update system catalogs */
3150 ATRewriteCatalogs(&wqueue, lockmode);
3151
3152 /* Phase 3: scan/rewrite tables as needed */
3153 ATRewriteTables(parsetree, &wqueue, lockmode);
3154 }
3155
3156 /*
3157 * ATPrepCmd
3158 *
3159 * Traffic cop for ALTER TABLE Phase 1 operations, including simple
3160 * recursion and permission checks.
3161 *
3162 * Caller must have acquired appropriate lock type on relation already.
3163 * This lock should be held until commit.
3164 */
3165 static void
ATPrepCmd(List ** wqueue,Relation rel,AlterTableCmd * cmd,bool recurse,bool recursing,LOCKMODE lockmode)3166 ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
3167 bool recurse, bool recursing, LOCKMODE lockmode)
3168 {
3169 AlteredTableInfo *tab;
3170 int pass = AT_PASS_UNSET;
3171
3172 /* Find or create work queue entry for this table */
3173 tab = ATGetQueueEntry(wqueue, rel);
3174
3175 /*
3176 * Copy the original subcommand for each table. This avoids conflicts
3177 * when different child tables need to make different parse
3178 * transformations (for example, the same column may have different column
3179 * numbers in different children).
3180 */
3181 cmd = copyObject(cmd);
3182
3183 /*
3184 * Do permissions checking, recursion to child tables if needed, and any
3185 * additional phase-1 processing needed.
3186 */
3187 switch (cmd->subtype)
3188 {
3189 case AT_AddColumn: /* ADD COLUMN */
3190 ATSimplePermissions(rel,
3191 ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
3192 ATPrepAddColumn(wqueue, rel, recurse, recursing, false, cmd,
3193 lockmode);
3194 /* Recursion occurs during execution phase */
3195 pass = AT_PASS_ADD_COL;
3196 break;
3197 case AT_AddColumnToView: /* add column via CREATE OR REPLACE
3198 * VIEW */
3199 ATSimplePermissions(rel, ATT_VIEW);
3200 ATPrepAddColumn(wqueue, rel, recurse, recursing, true, cmd,
3201 lockmode);
3202 /* Recursion occurs during execution phase */
3203 pass = AT_PASS_ADD_COL;
3204 break;
3205 case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */
3206
3207 /*
3208 * We allow defaults on views so that INSERT into a view can have
3209 * default-ish behavior. This works because the rewriter
3210 * substitutes default values into INSERTs before it expands
3211 * rules.
3212 */
3213 ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
3214 ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
3215 /* No command-specific prep needed */
3216 pass = cmd->def ? AT_PASS_ADD_CONSTR : AT_PASS_DROP;
3217 break;
3218 case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */
3219 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3220 ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
3221 /* No command-specific prep needed */
3222 pass = AT_PASS_DROP;
3223 break;
3224 case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */
3225 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3226 ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
3227 /* No command-specific prep needed */
3228 pass = AT_PASS_ADD_CONSTR;
3229 break;
3230 case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */
3231 ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
3232 /* Performs own permission checks */
3233 ATPrepSetStatistics(rel, cmd->name, cmd->def, lockmode);
3234 pass = AT_PASS_MISC;
3235 break;
3236 case AT_SetOptions: /* ALTER COLUMN SET ( options ) */
3237 case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */
3238 ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE);
3239 /* This command never recurses */
3240 pass = AT_PASS_MISC;
3241 break;
3242 case AT_SetStorage: /* ALTER COLUMN SET STORAGE */
3243 ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE);
3244 ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
3245 /* No command-specific prep needed */
3246 pass = AT_PASS_MISC;
3247 break;
3248 case AT_DropColumn: /* DROP COLUMN */
3249 ATSimplePermissions(rel,
3250 ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
3251 ATPrepDropColumn(wqueue, rel, recurse, recursing, cmd, lockmode);
3252 /* Recursion occurs during execution phase */
3253 pass = AT_PASS_DROP;
3254 break;
3255 case AT_AddIndex: /* ADD INDEX */
3256 ATSimplePermissions(rel, ATT_TABLE);
3257 /* This command never recurses */
3258 /* No command-specific prep needed */
3259 pass = AT_PASS_ADD_INDEX;
3260 break;
3261 case AT_AddConstraint: /* ADD CONSTRAINT */
3262 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3263 /* Recursion occurs during execution phase */
3264 /* No command-specific prep needed except saving recurse flag */
3265 if (recurse)
3266 cmd->subtype = AT_AddConstraintRecurse;
3267 pass = AT_PASS_ADD_CONSTR;
3268 break;
3269 case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
3270 ATSimplePermissions(rel, ATT_TABLE);
3271 /* This command never recurses */
3272 /* No command-specific prep needed */
3273 pass = AT_PASS_ADD_CONSTR;
3274 break;
3275 case AT_DropConstraint: /* DROP CONSTRAINT */
3276 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3277 /* Recursion occurs during execution phase */
3278 /* No command-specific prep needed except saving recurse flag */
3279 if (recurse)
3280 cmd->subtype = AT_DropConstraintRecurse;
3281 pass = AT_PASS_DROP;
3282 break;
3283 case AT_AlterColumnType: /* ALTER COLUMN TYPE */
3284 ATSimplePermissions(rel,
3285 ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
3286 /* Performs own recursion */
3287 ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd, lockmode);
3288 pass = AT_PASS_ALTER_TYPE;
3289 break;
3290 case AT_AlterColumnGenericOptions:
3291 ATSimplePermissions(rel, ATT_FOREIGN_TABLE);
3292 /* This command never recurses */
3293 /* No command-specific prep needed */
3294 pass = AT_PASS_MISC;
3295 break;
3296 case AT_ChangeOwner: /* ALTER OWNER */
3297 /* This command never recurses */
3298 /* No command-specific prep needed */
3299 pass = AT_PASS_MISC;
3300 break;
3301 case AT_ClusterOn: /* CLUSTER ON */
3302 case AT_DropCluster: /* SET WITHOUT CLUSTER */
3303 ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
3304 /* These commands never recurse */
3305 /* No command-specific prep needed */
3306 pass = AT_PASS_MISC;
3307 break;
3308 case AT_SetLogged: /* SET LOGGED */
3309 ATSimplePermissions(rel, ATT_TABLE);
3310 tab->chgPersistence = ATPrepChangePersistence(rel, true);
3311 /* force rewrite if necessary; see comment in ATRewriteTables */
3312 if (tab->chgPersistence)
3313 {
3314 tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
3315 tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
3316 }
3317 pass = AT_PASS_MISC;
3318 break;
3319 case AT_SetUnLogged: /* SET UNLOGGED */
3320 ATSimplePermissions(rel, ATT_TABLE);
3321 tab->chgPersistence = ATPrepChangePersistence(rel, false);
3322 /* force rewrite if necessary; see comment in ATRewriteTables */
3323 if (tab->chgPersistence)
3324 {
3325 tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
3326 tab->newrelpersistence = RELPERSISTENCE_UNLOGGED;
3327 }
3328 pass = AT_PASS_MISC;
3329 break;
3330 case AT_AddOids: /* SET WITH OIDS */
3331 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3332 if (!rel->rd_rel->relhasoids || recursing)
3333 ATPrepAddOids(wqueue, rel, recurse, cmd, lockmode);
3334 /* Recursion occurs during execution phase */
3335 pass = AT_PASS_ADD_COL;
3336 break;
3337 case AT_DropOids: /* SET WITHOUT OIDS */
3338 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3339 /* Performs own recursion */
3340 if (rel->rd_rel->relhasoids)
3341 {
3342 AlterTableCmd *dropCmd = makeNode(AlterTableCmd);
3343
3344 dropCmd->subtype = AT_DropColumn;
3345 dropCmd->name = pstrdup("oid");
3346 dropCmd->behavior = cmd->behavior;
3347 ATPrepCmd(wqueue, rel, dropCmd, recurse, false, lockmode);
3348 }
3349 pass = AT_PASS_DROP;
3350 break;
3351 case AT_SetTableSpace: /* SET TABLESPACE */
3352 ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX);
3353 /* This command never recurses */
3354 ATPrepSetTableSpace(tab, rel, cmd->name, lockmode);
3355 pass = AT_PASS_MISC; /* doesn't actually matter */
3356 break;
3357 case AT_SetRelOptions: /* SET (...) */
3358 case AT_ResetRelOptions: /* RESET (...) */
3359 case AT_ReplaceRelOptions: /* reset them all, then set just these */
3360 ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX);
3361 /* This command never recurses */
3362 /* No command-specific prep needed */
3363 pass = AT_PASS_MISC;
3364 break;
3365 case AT_AddInherit: /* INHERIT */
3366 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3367 /* This command never recurses */
3368 ATPrepAddInherit(rel);
3369 pass = AT_PASS_MISC;
3370 break;
3371 case AT_DropInherit: /* NO INHERIT */
3372 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3373 /* This command never recurses */
3374 /* No command-specific prep needed */
3375 pass = AT_PASS_MISC;
3376 break;
3377 case AT_AlterConstraint: /* ALTER CONSTRAINT */
3378 ATSimplePermissions(rel, ATT_TABLE);
3379 pass = AT_PASS_MISC;
3380 break;
3381 case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
3382 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3383 /* Recursion occurs during execution phase */
3384 /* No command-specific prep needed except saving recurse flag */
3385 if (recurse)
3386 cmd->subtype = AT_ValidateConstraintRecurse;
3387 pass = AT_PASS_MISC;
3388 break;
3389 case AT_ReplicaIdentity: /* REPLICA IDENTITY ... */
3390 ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
3391 pass = AT_PASS_MISC;
3392 /* This command never recurses */
3393 /* No command-specific prep needed */
3394 break;
3395 case AT_EnableTrig: /* ENABLE TRIGGER variants */
3396 case AT_EnableAlwaysTrig:
3397 case AT_EnableReplicaTrig:
3398 case AT_EnableTrigAll:
3399 case AT_EnableTrigUser:
3400 case AT_DisableTrig: /* DISABLE TRIGGER variants */
3401 case AT_DisableTrigAll:
3402 case AT_DisableTrigUser:
3403 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
3404 pass = AT_PASS_MISC;
3405 break;
3406 case AT_EnableRule: /* ENABLE/DISABLE RULE variants */
3407 case AT_EnableAlwaysRule:
3408 case AT_EnableReplicaRule:
3409 case AT_DisableRule:
3410 case AT_AddOf: /* OF */
3411 case AT_DropOf: /* NOT OF */
3412 case AT_EnableRowSecurity:
3413 case AT_DisableRowSecurity:
3414 case AT_ForceRowSecurity:
3415 case AT_NoForceRowSecurity:
3416 ATSimplePermissions(rel, ATT_TABLE);
3417 /* These commands never recurse */
3418 /* No command-specific prep needed */
3419 pass = AT_PASS_MISC;
3420 break;
3421 case AT_GenericOptions:
3422 ATSimplePermissions(rel, ATT_FOREIGN_TABLE);
3423 /* No command-specific prep needed */
3424 pass = AT_PASS_MISC;
3425 break;
3426 default: /* oops */
3427 elog(ERROR, "unrecognized alter table type: %d",
3428 (int) cmd->subtype);
3429 pass = AT_PASS_UNSET; /* keep compiler quiet */
3430 break;
3431 }
3432 Assert(pass > AT_PASS_UNSET);
3433
3434 /* Add the subcommand to the appropriate list for phase 2 */
3435 tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd);
3436 }
3437
3438 /*
3439 * ATRewriteCatalogs
3440 *
3441 * Traffic cop for ALTER TABLE Phase 2 operations. Subcommands are
3442 * dispatched in a "safe" execution order (designed to avoid unnecessary
3443 * conflicts).
3444 */
3445 static void
ATRewriteCatalogs(List ** wqueue,LOCKMODE lockmode)3446 ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode)
3447 {
3448 int pass;
3449 ListCell *ltab;
3450
3451 /*
3452 * We process all the tables "in parallel", one pass at a time. This is
3453 * needed because we may have to propagate work from one table to another
3454 * (specifically, ALTER TYPE on a foreign key's PK has to dispatch the
3455 * re-adding of the foreign key constraint to the other table). Work can
3456 * only be propagated into later passes, however.
3457 */
3458 for (pass = 0; pass < AT_NUM_PASSES; pass++)
3459 {
3460 /* Go through each table that needs to be processed */
3461 foreach(ltab, *wqueue)
3462 {
3463 AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
3464 List *subcmds = tab->subcmds[pass];
3465 Relation rel;
3466 ListCell *lcmd;
3467
3468 if (subcmds == NIL)
3469 continue;
3470
3471 /*
3472 * Appropriate lock was obtained by phase 1, needn't get it again
3473 */
3474 rel = relation_open(tab->relid, NoLock);
3475
3476 foreach(lcmd, subcmds)
3477 ATExecCmd(wqueue, tab, rel, (AlterTableCmd *) lfirst(lcmd), lockmode);
3478
3479 /*
3480 * After the ALTER TYPE pass, do cleanup work (this is not done in
3481 * ATExecAlterColumnType since it should be done only once if
3482 * multiple columns of a table are altered).
3483 */
3484 if (pass == AT_PASS_ALTER_TYPE)
3485 ATPostAlterTypeCleanup(wqueue, tab, lockmode);
3486
3487 relation_close(rel, NoLock);
3488 }
3489 }
3490
3491 /* Check to see if a toast table must be added. */
3492 foreach(ltab, *wqueue)
3493 {
3494 AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
3495
3496 if (tab->relkind == RELKIND_RELATION ||
3497 tab->relkind == RELKIND_MATVIEW)
3498 AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode);
3499 }
3500 }
3501
3502 /*
3503 * ATExecCmd: dispatch a subcommand to appropriate execution routine
3504 */
3505 static void
ATExecCmd(List ** wqueue,AlteredTableInfo * tab,Relation rel,AlterTableCmd * cmd,LOCKMODE lockmode)3506 ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
3507 AlterTableCmd *cmd, LOCKMODE lockmode)
3508 {
3509 ObjectAddress address = InvalidObjectAddress;
3510
3511 switch (cmd->subtype)
3512 {
3513 case AT_AddColumn: /* ADD COLUMN */
3514 case AT_AddColumnToView: /* add column via CREATE OR REPLACE
3515 * VIEW */
3516 address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
3517 false, false, false,
3518 cmd->missing_ok, lockmode);
3519 break;
3520 case AT_AddColumnRecurse:
3521 address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
3522 false, true, false,
3523 cmd->missing_ok, lockmode);
3524 break;
3525 case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */
3526 address = ATExecColumnDefault(rel, cmd->name, cmd->def, lockmode);
3527 break;
3528 case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */
3529 address = ATExecDropNotNull(rel, cmd->name, lockmode);
3530 break;
3531 case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */
3532 address = ATExecSetNotNull(tab, rel, cmd->name, lockmode);
3533 break;
3534 case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */
3535 address = ATExecSetStatistics(rel, cmd->name, cmd->def, lockmode);
3536 break;
3537 case AT_SetOptions: /* ALTER COLUMN SET ( options ) */
3538 address = ATExecSetOptions(rel, cmd->name, cmd->def, false, lockmode);
3539 break;
3540 case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */
3541 address = ATExecSetOptions(rel, cmd->name, cmd->def, true, lockmode);
3542 break;
3543 case AT_SetStorage: /* ALTER COLUMN SET STORAGE */
3544 address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode);
3545 break;
3546 case AT_DropColumn: /* DROP COLUMN */
3547 address = ATExecDropColumn(wqueue, rel, cmd->name,
3548 cmd->behavior, false, false,
3549 cmd->missing_ok, lockmode);
3550 break;
3551 case AT_DropColumnRecurse: /* DROP COLUMN with recursion */
3552 address = ATExecDropColumn(wqueue, rel, cmd->name,
3553 cmd->behavior, true, false,
3554 cmd->missing_ok, lockmode);
3555 break;
3556 case AT_AddIndex: /* ADD INDEX */
3557 address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, false,
3558 lockmode);
3559 break;
3560 case AT_ReAddIndex: /* ADD INDEX */
3561 address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true,
3562 lockmode);
3563 break;
3564 case AT_AddConstraint: /* ADD CONSTRAINT */
3565 address =
3566 ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
3567 false, false, lockmode);
3568 break;
3569 case AT_AddConstraintRecurse: /* ADD CONSTRAINT with recursion */
3570 address =
3571 ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
3572 true, false, lockmode);
3573 break;
3574 case AT_ReAddConstraint: /* Re-add pre-existing check
3575 * constraint */
3576 address =
3577 ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
3578 true, true, lockmode);
3579 break;
3580 case AT_ReAddComment: /* Re-add existing comment */
3581 address = CommentObject((CommentStmt *) cmd->def);
3582 break;
3583 case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
3584 address = ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def,
3585 lockmode);
3586 break;
3587 case AT_AlterConstraint: /* ALTER CONSTRAINT */
3588 address = ATExecAlterConstraint(rel, cmd, false, false, lockmode);
3589 break;
3590 case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
3591 address = ATExecValidateConstraint(wqueue, rel, cmd->name, false,
3592 false, lockmode);
3593 break;
3594 case AT_ValidateConstraintRecurse: /* VALIDATE CONSTRAINT with
3595 * recursion */
3596 address = ATExecValidateConstraint(wqueue, rel, cmd->name, true,
3597 false, lockmode);
3598 break;
3599 case AT_DropConstraint: /* DROP CONSTRAINT */
3600 ATExecDropConstraint(rel, cmd->name, cmd->behavior,
3601 false, false,
3602 cmd->missing_ok, lockmode);
3603 break;
3604 case AT_DropConstraintRecurse: /* DROP CONSTRAINT with recursion */
3605 ATExecDropConstraint(rel, cmd->name, cmd->behavior,
3606 true, false,
3607 cmd->missing_ok, lockmode);
3608 break;
3609 case AT_AlterColumnType: /* ALTER COLUMN TYPE */
3610 address = ATExecAlterColumnType(tab, rel, cmd, lockmode);
3611 break;
3612 case AT_AlterColumnGenericOptions: /* ALTER COLUMN OPTIONS */
3613 address =
3614 ATExecAlterColumnGenericOptions(rel, cmd->name,
3615 (List *) cmd->def, lockmode);
3616 break;
3617 case AT_ChangeOwner: /* ALTER OWNER */
3618 ATExecChangeOwner(RelationGetRelid(rel),
3619 get_rolespec_oid(cmd->newowner, false),
3620 false, lockmode);
3621 break;
3622 case AT_ClusterOn: /* CLUSTER ON */
3623 address = ATExecClusterOn(rel, cmd->name, lockmode);
3624 break;
3625 case AT_DropCluster: /* SET WITHOUT CLUSTER */
3626 ATExecDropCluster(rel, lockmode);
3627 break;
3628 case AT_SetLogged: /* SET LOGGED */
3629 case AT_SetUnLogged: /* SET UNLOGGED */
3630 break;
3631 case AT_AddOids: /* SET WITH OIDS */
3632 /* Use the ADD COLUMN code, unless prep decided to do nothing */
3633 if (cmd->def != NULL)
3634 address =
3635 ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
3636 true, false, false,
3637 cmd->missing_ok, lockmode);
3638 break;
3639 case AT_AddOidsRecurse: /* SET WITH OIDS */
3640 /* Use the ADD COLUMN code, unless prep decided to do nothing */
3641 if (cmd->def != NULL)
3642 address =
3643 ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
3644 true, true, false,
3645 cmd->missing_ok, lockmode);
3646 break;
3647 case AT_DropOids: /* SET WITHOUT OIDS */
3648
3649 /*
3650 * Nothing to do here; we'll have generated a DropColumn
3651 * subcommand to do the real work
3652 */
3653 break;
3654 case AT_SetTableSpace: /* SET TABLESPACE */
3655
3656 /*
3657 * Nothing to do here; Phase 3 does the work
3658 */
3659 break;
3660 case AT_SetRelOptions: /* SET (...) */
3661 case AT_ResetRelOptions: /* RESET (...) */
3662 case AT_ReplaceRelOptions: /* replace entire option list */
3663 ATExecSetRelOptions(rel, (List *) cmd->def, cmd->subtype, lockmode);
3664 break;
3665 case AT_EnableTrig: /* ENABLE TRIGGER name */
3666 ATExecEnableDisableTrigger(rel, cmd->name,
3667 TRIGGER_FIRES_ON_ORIGIN, false, lockmode);
3668 break;
3669 case AT_EnableAlwaysTrig: /* ENABLE ALWAYS TRIGGER name */
3670 ATExecEnableDisableTrigger(rel, cmd->name,
3671 TRIGGER_FIRES_ALWAYS, false, lockmode);
3672 break;
3673 case AT_EnableReplicaTrig: /* ENABLE REPLICA TRIGGER name */
3674 ATExecEnableDisableTrigger(rel, cmd->name,
3675 TRIGGER_FIRES_ON_REPLICA, false, lockmode);
3676 break;
3677 case AT_DisableTrig: /* DISABLE TRIGGER name */
3678 ATExecEnableDisableTrigger(rel, cmd->name,
3679 TRIGGER_DISABLED, false, lockmode);
3680 break;
3681 case AT_EnableTrigAll: /* ENABLE TRIGGER ALL */
3682 ATExecEnableDisableTrigger(rel, NULL,
3683 TRIGGER_FIRES_ON_ORIGIN, false, lockmode);
3684 break;
3685 case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */
3686 ATExecEnableDisableTrigger(rel, NULL,
3687 TRIGGER_DISABLED, false, lockmode);
3688 break;
3689 case AT_EnableTrigUser: /* ENABLE TRIGGER USER */
3690 ATExecEnableDisableTrigger(rel, NULL,
3691 TRIGGER_FIRES_ON_ORIGIN, true, lockmode);
3692 break;
3693 case AT_DisableTrigUser: /* DISABLE TRIGGER USER */
3694 ATExecEnableDisableTrigger(rel, NULL,
3695 TRIGGER_DISABLED, true, lockmode);
3696 break;
3697
3698 case AT_EnableRule: /* ENABLE RULE name */
3699 ATExecEnableDisableRule(rel, cmd->name,
3700 RULE_FIRES_ON_ORIGIN, lockmode);
3701 break;
3702 case AT_EnableAlwaysRule: /* ENABLE ALWAYS RULE name */
3703 ATExecEnableDisableRule(rel, cmd->name,
3704 RULE_FIRES_ALWAYS, lockmode);
3705 break;
3706 case AT_EnableReplicaRule: /* ENABLE REPLICA RULE name */
3707 ATExecEnableDisableRule(rel, cmd->name,
3708 RULE_FIRES_ON_REPLICA, lockmode);
3709 break;
3710 case AT_DisableRule: /* DISABLE RULE name */
3711 ATExecEnableDisableRule(rel, cmd->name,
3712 RULE_DISABLED, lockmode);
3713 break;
3714
3715 case AT_AddInherit:
3716 address = ATExecAddInherit(rel, (RangeVar *) cmd->def, lockmode);
3717 break;
3718 case AT_DropInherit:
3719 address = ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode);
3720 break;
3721 case AT_AddOf:
3722 address = ATExecAddOf(rel, (TypeName *) cmd->def, lockmode);
3723 break;
3724 case AT_DropOf:
3725 ATExecDropOf(rel, lockmode);
3726 break;
3727 case AT_ReplicaIdentity:
3728 ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode);
3729 break;
3730 case AT_EnableRowSecurity:
3731 ATExecEnableRowSecurity(rel);
3732 break;
3733 case AT_DisableRowSecurity:
3734 ATExecDisableRowSecurity(rel);
3735 break;
3736 case AT_ForceRowSecurity:
3737 ATExecForceNoForceRowSecurity(rel, true);
3738 break;
3739 case AT_NoForceRowSecurity:
3740 ATExecForceNoForceRowSecurity(rel, false);
3741 break;
3742 case AT_GenericOptions:
3743 ATExecGenericOptions(rel, (List *) cmd->def);
3744 break;
3745 default: /* oops */
3746 elog(ERROR, "unrecognized alter table type: %d",
3747 (int) cmd->subtype);
3748 break;
3749 }
3750
3751 /*
3752 * Report the subcommand to interested event triggers.
3753 */
3754 EventTriggerCollectAlterTableSubcmd((Node *) cmd, address);
3755
3756 /*
3757 * Bump the command counter to ensure the next subcommand in the sequence
3758 * can see the changes so far
3759 */
3760 CommandCounterIncrement();
3761 }
3762
3763 /*
3764 * ATRewriteTables: ALTER TABLE phase 3
3765 */
3766 static void
ATRewriteTables(AlterTableStmt * parsetree,List ** wqueue,LOCKMODE lockmode)3767 ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode)
3768 {
3769 ListCell *ltab;
3770
3771 /* Go through each table that needs to be checked or rewritten */
3772 foreach(ltab, *wqueue)
3773 {
3774 AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
3775
3776 /* Foreign tables have no storage. */
3777 if (tab->relkind == RELKIND_FOREIGN_TABLE)
3778 continue;
3779
3780 /*
3781 * If we change column data types or add/remove OIDs, the operation
3782 * has to be propagated to tables that use this table's rowtype as a
3783 * column type. tab->newvals will also be non-NULL in the case where
3784 * we're adding a column with a default. We choose to forbid that
3785 * case as well, since composite types might eventually support
3786 * defaults.
3787 *
3788 * (Eventually we'll probably need to check for composite type
3789 * dependencies even when we're just scanning the table without a
3790 * rewrite, but at the moment a composite type does not enforce any
3791 * constraints, so it's not necessary/appropriate to enforce them just
3792 * during ALTER.)
3793 */
3794 if (tab->newvals != NIL || tab->rewrite > 0)
3795 {
3796 Relation rel;
3797
3798 rel = heap_open(tab->relid, NoLock);
3799 find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
3800 heap_close(rel, NoLock);
3801 }
3802
3803 /*
3804 * We only need to rewrite the table if at least one column needs to
3805 * be recomputed, we are adding/removing the OID column, or we are
3806 * changing its persistence.
3807 *
3808 * There are two reasons for requiring a rewrite when changing
3809 * persistence: on one hand, we need to ensure that the buffers
3810 * belonging to each of the two relations are marked with or without
3811 * BM_PERMANENT properly. On the other hand, since rewriting creates
3812 * and assigns a new relfilenode, we automatically create or drop an
3813 * init fork for the relation as appropriate.
3814 */
3815 if (tab->rewrite > 0)
3816 {
3817 /* Build a temporary relation and copy data */
3818 Relation OldHeap;
3819 Oid OIDNewHeap;
3820 Oid NewTableSpace;
3821 char persistence;
3822
3823 OldHeap = heap_open(tab->relid, NoLock);
3824
3825 /*
3826 * We don't support rewriting of system catalogs; there are too
3827 * many corner cases and too little benefit. In particular this
3828 * is certainly not going to work for mapped catalogs.
3829 */
3830 if (IsSystemRelation(OldHeap))
3831 ereport(ERROR,
3832 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3833 errmsg("cannot rewrite system relation \"%s\"",
3834 RelationGetRelationName(OldHeap))));
3835
3836 if (RelationIsUsedAsCatalogTable(OldHeap))
3837 ereport(ERROR,
3838 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3839 errmsg("cannot rewrite table \"%s\" used as a catalog table",
3840 RelationGetRelationName(OldHeap))));
3841
3842 /*
3843 * Don't allow rewrite on temp tables of other backends ... their
3844 * local buffer manager is not going to cope.
3845 */
3846 if (RELATION_IS_OTHER_TEMP(OldHeap))
3847 ereport(ERROR,
3848 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3849 errmsg("cannot rewrite temporary tables of other sessions")));
3850
3851 /*
3852 * Select destination tablespace (same as original unless user
3853 * requested a change)
3854 */
3855 if (tab->newTableSpace)
3856 NewTableSpace = tab->newTableSpace;
3857 else
3858 NewTableSpace = OldHeap->rd_rel->reltablespace;
3859
3860 /*
3861 * Select persistence of transient table (same as original unless
3862 * user requested a change)
3863 */
3864 persistence = tab->chgPersistence ?
3865 tab->newrelpersistence : OldHeap->rd_rel->relpersistence;
3866
3867 heap_close(OldHeap, NoLock);
3868
3869 /*
3870 * Fire off an Event Trigger now, before actually rewriting the
3871 * table.
3872 *
3873 * We don't support Event Trigger for nested commands anywhere,
3874 * here included, and parsetree is given NULL when coming from
3875 * AlterTableInternal.
3876 *
3877 * And fire it only once.
3878 */
3879 if (parsetree)
3880 EventTriggerTableRewrite((Node *) parsetree,
3881 tab->relid,
3882 tab->rewrite);
3883
3884 /*
3885 * Create transient table that will receive the modified data.
3886 *
3887 * Ensure it is marked correctly as logged or unlogged. We have
3888 * to do this here so that buffers for the new relfilenode will
3889 * have the right persistence set, and at the same time ensure
3890 * that the original filenode's buffers will get read in with the
3891 * correct setting (i.e. the original one). Otherwise a rollback
3892 * after the rewrite would possibly result with buffers for the
3893 * original filenode having the wrong persistence setting.
3894 *
3895 * NB: This relies on swap_relation_files() also swapping the
3896 * persistence. That wouldn't work for pg_class, but that can't be
3897 * unlogged anyway.
3898 */
3899 OIDNewHeap = make_new_heap(tab->relid, NewTableSpace, persistence,
3900 lockmode);
3901
3902 /*
3903 * Copy the heap data into the new table with the desired
3904 * modifications, and test the current data within the table
3905 * against new constraints generated by ALTER TABLE commands.
3906 */
3907 ATRewriteTable(tab, OIDNewHeap, lockmode);
3908
3909 /*
3910 * Swap the physical files of the old and new heaps, then rebuild
3911 * indexes and discard the old heap. We can use RecentXmin for
3912 * the table's new relfrozenxid because we rewrote all the tuples
3913 * in ATRewriteTable, so no older Xid remains in the table. Also,
3914 * we never try to swap toast tables by content, since we have no
3915 * interest in letting this code work on system catalogs.
3916 */
3917 finish_heap_swap(tab->relid, OIDNewHeap,
3918 false, false, true,
3919 !OidIsValid(tab->newTableSpace),
3920 RecentXmin,
3921 ReadNextMultiXactId(),
3922 persistence);
3923 }
3924 else
3925 {
3926 /*
3927 * Test the current data within the table against new constraints
3928 * generated by ALTER TABLE commands, but don't rebuild data.
3929 */
3930 if (tab->constraints != NIL || tab->new_notnull)
3931 ATRewriteTable(tab, InvalidOid, lockmode);
3932
3933 /*
3934 * If we had SET TABLESPACE but no reason to reconstruct tuples,
3935 * just do a block-by-block copy.
3936 */
3937 if (tab->newTableSpace)
3938 ATExecSetTableSpace(tab->relid, tab->newTableSpace, lockmode);
3939 }
3940 }
3941
3942 /*
3943 * Foreign key constraints are checked in a final pass, since (a) it's
3944 * generally best to examine each one separately, and (b) it's at least
3945 * theoretically possible that we have changed both relations of the
3946 * foreign key, and we'd better have finished both rewrites before we try
3947 * to read the tables.
3948 */
3949 foreach(ltab, *wqueue)
3950 {
3951 AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
3952 Relation rel = NULL;
3953 ListCell *lcon;
3954
3955 foreach(lcon, tab->constraints)
3956 {
3957 NewConstraint *con = lfirst(lcon);
3958
3959 if (con->contype == CONSTR_FOREIGN)
3960 {
3961 Constraint *fkconstraint = (Constraint *) con->qual;
3962 Relation refrel;
3963
3964 if (rel == NULL)
3965 {
3966 /* Long since locked, no need for another */
3967 rel = heap_open(tab->relid, NoLock);
3968 }
3969
3970 refrel = heap_open(con->refrelid, RowShareLock);
3971
3972 validateForeignKeyConstraint(fkconstraint->conname, rel, refrel,
3973 con->refindid,
3974 con->conid);
3975
3976 /*
3977 * No need to mark the constraint row as validated, we did
3978 * that when we inserted the row earlier.
3979 */
3980
3981 heap_close(refrel, NoLock);
3982 }
3983 }
3984
3985 if (rel)
3986 heap_close(rel, NoLock);
3987 }
3988 }
3989
3990 /*
3991 * ATRewriteTable: scan or rewrite one table
3992 *
3993 * OIDNewHeap is InvalidOid if we don't need to rewrite
3994 */
3995 static void
ATRewriteTable(AlteredTableInfo * tab,Oid OIDNewHeap,LOCKMODE lockmode)3996 ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
3997 {
3998 Relation oldrel;
3999 Relation newrel;
4000 TupleDesc oldTupDesc;
4001 TupleDesc newTupDesc;
4002 bool needscan = false;
4003 List *notnull_attrs;
4004 int i;
4005 ListCell *l;
4006 EState *estate;
4007 CommandId mycid;
4008 BulkInsertState bistate;
4009 int hi_options;
4010
4011 /*
4012 * Open the relation(s). We have surely already locked the existing
4013 * table.
4014 */
4015 oldrel = heap_open(tab->relid, NoLock);
4016 oldTupDesc = tab->oldDesc;
4017 newTupDesc = RelationGetDescr(oldrel); /* includes all mods */
4018
4019 if (OidIsValid(OIDNewHeap))
4020 newrel = heap_open(OIDNewHeap, lockmode);
4021 else
4022 newrel = NULL;
4023
4024 /*
4025 * Prepare a BulkInsertState and options for heap_insert. Because we're
4026 * building a new heap, we can skip WAL-logging and fsync it to disk at
4027 * the end instead (unless WAL-logging is required for archiving or
4028 * streaming replication). The FSM is empty too, so don't bother using it.
4029 */
4030 if (newrel)
4031 {
4032 mycid = GetCurrentCommandId(true);
4033 bistate = GetBulkInsertState();
4034
4035 hi_options = HEAP_INSERT_SKIP_FSM;
4036 if (!XLogIsNeeded())
4037 hi_options |= HEAP_INSERT_SKIP_WAL;
4038 }
4039 else
4040 {
4041 /* keep compiler quiet about using these uninitialized */
4042 mycid = 0;
4043 bistate = NULL;
4044 hi_options = 0;
4045 }
4046
4047 /*
4048 * Generate the constraint and default execution states
4049 */
4050
4051 estate = CreateExecutorState();
4052
4053 /* Build the needed expression execution states */
4054 foreach(l, tab->constraints)
4055 {
4056 NewConstraint *con = lfirst(l);
4057
4058 switch (con->contype)
4059 {
4060 case CONSTR_CHECK:
4061 needscan = true;
4062 con->qualstate = (List *)
4063 ExecPrepareExpr((Expr *) con->qual, estate);
4064 break;
4065 case CONSTR_FOREIGN:
4066 /* Nothing to do here */
4067 break;
4068 default:
4069 elog(ERROR, "unrecognized constraint type: %d",
4070 (int) con->contype);
4071 }
4072 }
4073
4074 foreach(l, tab->newvals)
4075 {
4076 NewColumnValue *ex = lfirst(l);
4077
4078 /* expr already planned */
4079 ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL);
4080 }
4081
4082 notnull_attrs = NIL;
4083 if (newrel || tab->new_notnull)
4084 {
4085 /*
4086 * If we are rebuilding the tuples OR if we added any new NOT NULL
4087 * constraints, check all not-null constraints. This is a bit of
4088 * overkill but it minimizes risk of bugs, and heap_attisnull is a
4089 * pretty cheap test anyway.
4090 */
4091 for (i = 0; i < newTupDesc->natts; i++)
4092 {
4093 if (newTupDesc->attrs[i]->attnotnull &&
4094 !newTupDesc->attrs[i]->attisdropped)
4095 notnull_attrs = lappend_int(notnull_attrs, i);
4096 }
4097 if (notnull_attrs)
4098 needscan = true;
4099 }
4100
4101 if (newrel || needscan)
4102 {
4103 ExprContext *econtext;
4104 Datum *values;
4105 bool *isnull;
4106 TupleTableSlot *oldslot;
4107 TupleTableSlot *newslot;
4108 HeapScanDesc scan;
4109 HeapTuple tuple;
4110 MemoryContext oldCxt;
4111 List *dropped_attrs = NIL;
4112 ListCell *lc;
4113 Snapshot snapshot;
4114
4115 if (newrel)
4116 ereport(DEBUG1,
4117 (errmsg("rewriting table \"%s\"",
4118 RelationGetRelationName(oldrel))));
4119 else
4120 ereport(DEBUG1,
4121 (errmsg("verifying table \"%s\"",
4122 RelationGetRelationName(oldrel))));
4123
4124 if (newrel)
4125 {
4126 /*
4127 * All predicate locks on the tuples or pages are about to be made
4128 * invalid, because we move tuples around. Promote them to
4129 * relation locks.
4130 */
4131 TransferPredicateLocksToHeapRelation(oldrel);
4132 }
4133
4134 econtext = GetPerTupleExprContext(estate);
4135
4136 /*
4137 * Make tuple slots for old and new tuples. Note that even when the
4138 * tuples are the same, the tupDescs might not be (consider ADD COLUMN
4139 * without a default).
4140 */
4141 oldslot = MakeSingleTupleTableSlot(oldTupDesc);
4142 newslot = MakeSingleTupleTableSlot(newTupDesc);
4143
4144 /* Preallocate values/isnull arrays */
4145 i = Max(newTupDesc->natts, oldTupDesc->natts);
4146 values = (Datum *) palloc(i * sizeof(Datum));
4147 isnull = (bool *) palloc(i * sizeof(bool));
4148 memset(values, 0, i * sizeof(Datum));
4149 memset(isnull, true, i * sizeof(bool));
4150
4151 /*
4152 * Any attributes that are dropped according to the new tuple
4153 * descriptor can be set to NULL. We precompute the list of dropped
4154 * attributes to avoid needing to do so in the per-tuple loop.
4155 */
4156 for (i = 0; i < newTupDesc->natts; i++)
4157 {
4158 if (newTupDesc->attrs[i]->attisdropped)
4159 dropped_attrs = lappend_int(dropped_attrs, i);
4160 }
4161
4162 /*
4163 * Scan through the rows, generating a new row if needed and then
4164 * checking all the constraints.
4165 */
4166 snapshot = RegisterSnapshot(GetLatestSnapshot());
4167 scan = heap_beginscan(oldrel, snapshot, 0, NULL);
4168
4169 /*
4170 * Switch to per-tuple memory context and reset it for each tuple
4171 * produced, so we don't leak memory.
4172 */
4173 oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
4174
4175 while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
4176 {
4177 if (tab->rewrite > 0)
4178 {
4179 Oid tupOid = InvalidOid;
4180
4181 /* Extract data from old tuple */
4182 heap_deform_tuple(tuple, oldTupDesc, values, isnull);
4183 if (oldTupDesc->tdhasoid)
4184 tupOid = HeapTupleGetOid(tuple);
4185
4186 /* Set dropped attributes to null in new tuple */
4187 foreach(lc, dropped_attrs)
4188 isnull[lfirst_int(lc)] = true;
4189
4190 /*
4191 * Process supplied expressions to replace selected columns.
4192 * Expression inputs come from the old tuple.
4193 */
4194 ExecStoreTuple(tuple, oldslot, InvalidBuffer, false);
4195 econtext->ecxt_scantuple = oldslot;
4196
4197 foreach(l, tab->newvals)
4198 {
4199 NewColumnValue *ex = lfirst(l);
4200
4201 values[ex->attnum - 1] = ExecEvalExpr(ex->exprstate,
4202 econtext,
4203 &isnull[ex->attnum - 1],
4204 NULL);
4205 }
4206
4207 /*
4208 * Form the new tuple. Note that we don't explicitly pfree it,
4209 * since the per-tuple memory context will be reset shortly.
4210 */
4211 tuple = heap_form_tuple(newTupDesc, values, isnull);
4212
4213 /* Preserve OID, if any */
4214 if (newTupDesc->tdhasoid)
4215 HeapTupleSetOid(tuple, tupOid);
4216
4217 /*
4218 * Constraints might reference the tableoid column, so
4219 * initialize t_tableOid before evaluating them.
4220 */
4221 tuple->t_tableOid = RelationGetRelid(oldrel);
4222 }
4223
4224 /* Now check any constraints on the possibly-changed tuple */
4225 ExecStoreTuple(tuple, newslot, InvalidBuffer, false);
4226 econtext->ecxt_scantuple = newslot;
4227
4228 foreach(l, notnull_attrs)
4229 {
4230 int attn = lfirst_int(l);
4231
4232 if (heap_attisnull(tuple, attn + 1))
4233 ereport(ERROR,
4234 (errcode(ERRCODE_NOT_NULL_VIOLATION),
4235 errmsg("column \"%s\" contains null values",
4236 NameStr(newTupDesc->attrs[attn]->attname)),
4237 errtablecol(oldrel, attn + 1)));
4238 }
4239
4240 foreach(l, tab->constraints)
4241 {
4242 NewConstraint *con = lfirst(l);
4243
4244 switch (con->contype)
4245 {
4246 case CONSTR_CHECK:
4247 if (!ExecQual(con->qualstate, econtext, true))
4248 ereport(ERROR,
4249 (errcode(ERRCODE_CHECK_VIOLATION),
4250 errmsg("check constraint \"%s\" is violated by some row",
4251 con->name),
4252 errtableconstraint(oldrel, con->name)));
4253 break;
4254 case CONSTR_FOREIGN:
4255 /* Nothing to do here */
4256 break;
4257 default:
4258 elog(ERROR, "unrecognized constraint type: %d",
4259 (int) con->contype);
4260 }
4261 }
4262
4263 /* Write the tuple out to the new relation */
4264 if (newrel)
4265 heap_insert(newrel, tuple, mycid, hi_options, bistate);
4266
4267 ResetExprContext(econtext);
4268
4269 CHECK_FOR_INTERRUPTS();
4270 }
4271
4272 MemoryContextSwitchTo(oldCxt);
4273 heap_endscan(scan);
4274 UnregisterSnapshot(snapshot);
4275
4276 ExecDropSingleTupleTableSlot(oldslot);
4277 ExecDropSingleTupleTableSlot(newslot);
4278 }
4279
4280 FreeExecutorState(estate);
4281
4282 heap_close(oldrel, NoLock);
4283 if (newrel)
4284 {
4285 FreeBulkInsertState(bistate);
4286
4287 /* If we skipped writing WAL, then we need to sync the heap. */
4288 if (hi_options & HEAP_INSERT_SKIP_WAL)
4289 heap_sync(newrel);
4290
4291 heap_close(newrel, NoLock);
4292 }
4293 }
4294
4295 /*
4296 * ATGetQueueEntry: find or create an entry in the ALTER TABLE work queue
4297 */
4298 static AlteredTableInfo *
ATGetQueueEntry(List ** wqueue,Relation rel)4299 ATGetQueueEntry(List **wqueue, Relation rel)
4300 {
4301 Oid relid = RelationGetRelid(rel);
4302 AlteredTableInfo *tab;
4303 ListCell *ltab;
4304
4305 foreach(ltab, *wqueue)
4306 {
4307 tab = (AlteredTableInfo *) lfirst(ltab);
4308 if (tab->relid == relid)
4309 return tab;
4310 }
4311
4312 /*
4313 * Not there, so add it. Note that we make a copy of the relation's
4314 * existing descriptor before anything interesting can happen to it.
4315 */
4316 tab = (AlteredTableInfo *) palloc0(sizeof(AlteredTableInfo));
4317 tab->relid = relid;
4318 tab->relkind = rel->rd_rel->relkind;
4319 tab->oldDesc = CreateTupleDescCopy(RelationGetDescr(rel));
4320 tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
4321 tab->chgPersistence = false;
4322
4323 *wqueue = lappend(*wqueue, tab);
4324
4325 return tab;
4326 }
4327
4328 /*
4329 * ATSimplePermissions
4330 *
4331 * - Ensure that it is a relation (or possibly a view)
4332 * - Ensure this user is the owner
4333 * - Ensure that it is not a system table
4334 */
4335 static void
ATSimplePermissions(Relation rel,int allowed_targets)4336 ATSimplePermissions(Relation rel, int allowed_targets)
4337 {
4338 int actual_target;
4339
4340 switch (rel->rd_rel->relkind)
4341 {
4342 case RELKIND_RELATION:
4343 actual_target = ATT_TABLE;
4344 break;
4345 case RELKIND_VIEW:
4346 actual_target = ATT_VIEW;
4347 break;
4348 case RELKIND_MATVIEW:
4349 actual_target = ATT_MATVIEW;
4350 break;
4351 case RELKIND_INDEX:
4352 actual_target = ATT_INDEX;
4353 break;
4354 case RELKIND_COMPOSITE_TYPE:
4355 actual_target = ATT_COMPOSITE_TYPE;
4356 break;
4357 case RELKIND_FOREIGN_TABLE:
4358 actual_target = ATT_FOREIGN_TABLE;
4359 break;
4360 default:
4361 actual_target = 0;
4362 break;
4363 }
4364
4365 /* Wrong target type? */
4366 if ((actual_target & allowed_targets) == 0)
4367 ATWrongRelkindError(rel, allowed_targets);
4368
4369 /* Permissions checks */
4370 if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
4371 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
4372 RelationGetRelationName(rel));
4373
4374 if (!allowSystemTableMods && IsSystemRelation(rel))
4375 ereport(ERROR,
4376 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4377 errmsg("permission denied: \"%s\" is a system catalog",
4378 RelationGetRelationName(rel))));
4379 }
4380
4381 /*
4382 * ATWrongRelkindError
4383 *
4384 * Throw an error when a relation has been determined to be of the wrong
4385 * type.
4386 */
4387 static void
ATWrongRelkindError(Relation rel,int allowed_targets)4388 ATWrongRelkindError(Relation rel, int allowed_targets)
4389 {
4390 char *msg;
4391
4392 switch (allowed_targets)
4393 {
4394 case ATT_TABLE:
4395 msg = _("\"%s\" is not a table");
4396 break;
4397 case ATT_TABLE | ATT_VIEW:
4398 msg = _("\"%s\" is not a table or view");
4399 break;
4400 case ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE:
4401 msg = _("\"%s\" is not a table, view, or foreign table");
4402 break;
4403 case ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX:
4404 msg = _("\"%s\" is not a table, view, materialized view, or index");
4405 break;
4406 case ATT_TABLE | ATT_MATVIEW:
4407 msg = _("\"%s\" is not a table or materialized view");
4408 break;
4409 case ATT_TABLE | ATT_MATVIEW | ATT_INDEX:
4410 msg = _("\"%s\" is not a table, materialized view, or index");
4411 break;
4412 case ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE:
4413 msg = _("\"%s\" is not a table, materialized view, or foreign table");
4414 break;
4415 case ATT_TABLE | ATT_FOREIGN_TABLE:
4416 msg = _("\"%s\" is not a table or foreign table");
4417 break;
4418 case ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE:
4419 msg = _("\"%s\" is not a table, composite type, or foreign table");
4420 break;
4421 case ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE:
4422 msg = _("\"%s\" is not a table, materialized view, index, or foreign table");
4423 break;
4424 case ATT_VIEW:
4425 msg = _("\"%s\" is not a view");
4426 break;
4427 case ATT_FOREIGN_TABLE:
4428 msg = _("\"%s\" is not a foreign table");
4429 break;
4430 default:
4431 /* shouldn't get here, add all necessary cases above */
4432 msg = _("\"%s\" is of the wrong type");
4433 break;
4434 }
4435
4436 ereport(ERROR,
4437 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
4438 errmsg(msg, RelationGetRelationName(rel))));
4439 }
4440
4441 /*
4442 * ATSimpleRecursion
4443 *
4444 * Simple table recursion sufficient for most ALTER TABLE operations.
4445 * All direct and indirect children are processed in an unspecified order.
4446 * Note that if a child inherits from the original table via multiple
4447 * inheritance paths, it will be visited just once.
4448 */
4449 static void
ATSimpleRecursion(List ** wqueue,Relation rel,AlterTableCmd * cmd,bool recurse,LOCKMODE lockmode)4450 ATSimpleRecursion(List **wqueue, Relation rel,
4451 AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode)
4452 {
4453 /*
4454 * Propagate to children if desired. Only plain tables and foreign tables
4455 * have children, so no need to search for other relkinds.
4456 */
4457 if (recurse &&
4458 (rel->rd_rel->relkind == RELKIND_RELATION ||
4459 rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE))
4460 {
4461 Oid relid = RelationGetRelid(rel);
4462 ListCell *child;
4463 List *children;
4464
4465 children = find_all_inheritors(relid, lockmode, NULL);
4466
4467 /*
4468 * find_all_inheritors does the recursive search of the inheritance
4469 * hierarchy, so all we have to do is process all of the relids in the
4470 * list that it returns.
4471 */
4472 foreach(child, children)
4473 {
4474 Oid childrelid = lfirst_oid(child);
4475 Relation childrel;
4476
4477 if (childrelid == relid)
4478 continue;
4479 /* find_all_inheritors already got lock */
4480 childrel = relation_open(childrelid, NoLock);
4481 CheckTableNotInUse(childrel, "ALTER TABLE");
4482 ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode);
4483 relation_close(childrel, NoLock);
4484 }
4485 }
4486 }
4487
4488 /*
4489 * ATTypedTableRecursion
4490 *
4491 * Propagate ALTER TYPE operations to the typed tables of that type.
4492 * Also check the RESTRICT/CASCADE behavior. Given CASCADE, also permit
4493 * recursion to inheritance children of the typed tables.
4494 */
4495 static void
ATTypedTableRecursion(List ** wqueue,Relation rel,AlterTableCmd * cmd,LOCKMODE lockmode)4496 ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
4497 LOCKMODE lockmode)
4498 {
4499 ListCell *child;
4500 List *children;
4501
4502 Assert(rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
4503
4504 children = find_typed_table_dependencies(rel->rd_rel->reltype,
4505 RelationGetRelationName(rel),
4506 cmd->behavior);
4507
4508 foreach(child, children)
4509 {
4510 Oid childrelid = lfirst_oid(child);
4511 Relation childrel;
4512
4513 childrel = relation_open(childrelid, lockmode);
4514 CheckTableNotInUse(childrel, "ALTER TABLE");
4515 ATPrepCmd(wqueue, childrel, cmd, true, true, lockmode);
4516 relation_close(childrel, NoLock);
4517 }
4518 }
4519
4520
4521 /*
4522 * find_composite_type_dependencies
4523 *
4524 * Check to see if the type "typeOid" is being used as a column in some table
4525 * (possibly nested several levels deep in composite types, arrays, etc!).
4526 * Eventually, we'd like to propagate the check or rewrite operation
4527 * into such tables, but for now, just error out if we find any.
4528 *
4529 * Caller should provide either the associated relation of a rowtype,
4530 * or a type name (not both) for use in the error message, if any.
4531 *
4532 * Note that "typeOid" is not necessarily a composite type; it could also be
4533 * another container type such as an array or range, or a domain over one of
4534 * these things. The name of this function is therefore somewhat historical,
4535 * but it's not worth changing.
4536 *
4537 * We assume that functions and views depending on the type are not reasons
4538 * to reject the ALTER. (How safe is this really?)
4539 */
4540 void
find_composite_type_dependencies(Oid typeOid,Relation origRelation,const char * origTypeName)4541 find_composite_type_dependencies(Oid typeOid, Relation origRelation,
4542 const char *origTypeName)
4543 {
4544 Relation depRel;
4545 ScanKeyData key[2];
4546 SysScanDesc depScan;
4547 HeapTuple depTup;
4548
4549 /* since this function recurses, it could be driven to stack overflow */
4550 check_stack_depth();
4551
4552 /*
4553 * We scan pg_depend to find those things that depend on the given type.
4554 * (We assume we can ignore refobjsubid for a type.)
4555 */
4556 depRel = heap_open(DependRelationId, AccessShareLock);
4557
4558 ScanKeyInit(&key[0],
4559 Anum_pg_depend_refclassid,
4560 BTEqualStrategyNumber, F_OIDEQ,
4561 ObjectIdGetDatum(TypeRelationId));
4562 ScanKeyInit(&key[1],
4563 Anum_pg_depend_refobjid,
4564 BTEqualStrategyNumber, F_OIDEQ,
4565 ObjectIdGetDatum(typeOid));
4566
4567 depScan = systable_beginscan(depRel, DependReferenceIndexId, true,
4568 NULL, 2, key);
4569
4570 while (HeapTupleIsValid(depTup = systable_getnext(depScan)))
4571 {
4572 Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup);
4573 Relation rel;
4574 Form_pg_attribute att;
4575
4576 /* Check for directly dependent types */
4577 if (pg_depend->classid == TypeRelationId)
4578 {
4579 /*
4580 * This must be an array, domain, or range containing the given
4581 * type, so recursively check for uses of this type. Note that
4582 * any error message will mention the original type not the
4583 * container; this is intentional.
4584 */
4585 find_composite_type_dependencies(pg_depend->objid,
4586 origRelation, origTypeName);
4587 continue;
4588 }
4589
4590 /* Else, ignore dependees that aren't user columns of relations */
4591 /* (we assume system columns are never of interesting types) */
4592 if (pg_depend->classid != RelationRelationId ||
4593 pg_depend->objsubid <= 0)
4594 continue;
4595
4596 rel = relation_open(pg_depend->objid, AccessShareLock);
4597 att = rel->rd_att->attrs[pg_depend->objsubid - 1];
4598
4599 if (rel->rd_rel->relkind == RELKIND_RELATION ||
4600 rel->rd_rel->relkind == RELKIND_MATVIEW)
4601 {
4602 if (origTypeName)
4603 ereport(ERROR,
4604 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4605 errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
4606 origTypeName,
4607 RelationGetRelationName(rel),
4608 NameStr(att->attname))));
4609 else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
4610 ereport(ERROR,
4611 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4612 errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
4613 RelationGetRelationName(origRelation),
4614 RelationGetRelationName(rel),
4615 NameStr(att->attname))));
4616 else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
4617 ereport(ERROR,
4618 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4619 errmsg("cannot alter foreign table \"%s\" because column \"%s.%s\" uses its row type",
4620 RelationGetRelationName(origRelation),
4621 RelationGetRelationName(rel),
4622 NameStr(att->attname))));
4623 else
4624 ereport(ERROR,
4625 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4626 errmsg("cannot alter table \"%s\" because column \"%s.%s\" uses its row type",
4627 RelationGetRelationName(origRelation),
4628 RelationGetRelationName(rel),
4629 NameStr(att->attname))));
4630 }
4631 else if (OidIsValid(rel->rd_rel->reltype))
4632 {
4633 /*
4634 * A view or composite type itself isn't a problem, but we must
4635 * recursively check for indirect dependencies via its rowtype.
4636 */
4637 find_composite_type_dependencies(rel->rd_rel->reltype,
4638 origRelation, origTypeName);
4639 }
4640
4641 relation_close(rel, AccessShareLock);
4642 }
4643
4644 systable_endscan(depScan);
4645
4646 relation_close(depRel, AccessShareLock);
4647 }
4648
4649
4650 /*
4651 * find_typed_table_dependencies
4652 *
4653 * Check to see if a composite type is being used as the type of a
4654 * typed table. Abort if any are found and behavior is RESTRICT.
4655 * Else return the list of tables.
4656 */
4657 static List *
find_typed_table_dependencies(Oid typeOid,const char * typeName,DropBehavior behavior)4658 find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior)
4659 {
4660 Relation classRel;
4661 ScanKeyData key[1];
4662 HeapScanDesc scan;
4663 HeapTuple tuple;
4664 List *result = NIL;
4665
4666 classRel = heap_open(RelationRelationId, AccessShareLock);
4667
4668 ScanKeyInit(&key[0],
4669 Anum_pg_class_reloftype,
4670 BTEqualStrategyNumber, F_OIDEQ,
4671 ObjectIdGetDatum(typeOid));
4672
4673 scan = heap_beginscan_catalog(classRel, 1, key);
4674
4675 while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
4676 {
4677 if (behavior == DROP_RESTRICT)
4678 ereport(ERROR,
4679 (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
4680 errmsg("cannot alter type \"%s\" because it is the type of a typed table",
4681 typeName),
4682 errhint("Use ALTER ... CASCADE to alter the typed tables too.")));
4683 else
4684 result = lappend_oid(result, HeapTupleGetOid(tuple));
4685 }
4686
4687 heap_endscan(scan);
4688 heap_close(classRel, AccessShareLock);
4689
4690 return result;
4691 }
4692
4693
4694 /*
4695 * check_of_type
4696 *
4697 * Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF. If it
4698 * isn't suitable, throw an error. Currently, we require that the type
4699 * originated with CREATE TYPE AS. We could support any row type, but doing so
4700 * would require handling a number of extra corner cases in the DDL commands.
4701 */
4702 void
check_of_type(HeapTuple typetuple)4703 check_of_type(HeapTuple typetuple)
4704 {
4705 Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple);
4706 bool typeOk = false;
4707
4708 if (typ->typtype == TYPTYPE_COMPOSITE)
4709 {
4710 Relation typeRelation;
4711
4712 Assert(OidIsValid(typ->typrelid));
4713 typeRelation = relation_open(typ->typrelid, AccessShareLock);
4714 typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
4715
4716 /*
4717 * Close the parent rel, but keep our AccessShareLock on it until xact
4718 * commit. That will prevent someone else from deleting or ALTERing
4719 * the type before the typed table creation/conversion commits.
4720 */
4721 relation_close(typeRelation, NoLock);
4722 }
4723 if (!typeOk)
4724 ereport(ERROR,
4725 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
4726 errmsg("type %s is not a composite type",
4727 format_type_be(HeapTupleGetOid(typetuple)))));
4728 }
4729
4730
4731 /*
4732 * ALTER TABLE ADD COLUMN
4733 *
4734 * Adds an additional attribute to a relation making the assumption that
4735 * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the
4736 * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent
4737 * AlterTableCmd's.
4738 *
4739 * ADD COLUMN cannot use the normal ALTER TABLE recursion mechanism, because we
4740 * have to decide at runtime whether to recurse or not depending on whether we
4741 * actually add a column or merely merge with an existing column. (We can't
4742 * check this in a static pre-pass because it won't handle multiple inheritance
4743 * situations correctly.)
4744 */
4745 static void
ATPrepAddColumn(List ** wqueue,Relation rel,bool recurse,bool recursing,bool is_view,AlterTableCmd * cmd,LOCKMODE lockmode)4746 ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
4747 bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode)
4748 {
4749 if (rel->rd_rel->reloftype && !recursing)
4750 ereport(ERROR,
4751 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
4752 errmsg("cannot add column to typed table")));
4753
4754 if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
4755 ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
4756
4757 if (recurse && !is_view)
4758 cmd->subtype = AT_AddColumnRecurse;
4759 }
4760
4761 /*
4762 * Add a column to a table; this handles the AT_AddOids cases as well. The
4763 * return value is the address of the new column in the parent relation.
4764 */
4765 static ObjectAddress
ATExecAddColumn(List ** wqueue,AlteredTableInfo * tab,Relation rel,ColumnDef * colDef,bool isOid,bool recurse,bool recursing,bool if_not_exists,LOCKMODE lockmode)4766 ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
4767 ColumnDef *colDef, bool isOid,
4768 bool recurse, bool recursing,
4769 bool if_not_exists, LOCKMODE lockmode)
4770 {
4771 Oid myrelid = RelationGetRelid(rel);
4772 Relation pgclass,
4773 attrdesc;
4774 HeapTuple reltup;
4775 FormData_pg_attribute attribute;
4776 int newattnum;
4777 char relkind;
4778 HeapTuple typeTuple;
4779 Oid typeOid;
4780 int32 typmod;
4781 Oid collOid;
4782 Form_pg_type tform;
4783 Expr *defval;
4784 List *children;
4785 ListCell *child;
4786 AclResult aclresult;
4787 ObjectAddress address;
4788
4789 /* At top level, permission check was done in ATPrepCmd, else do it */
4790 if (recursing)
4791 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
4792
4793 attrdesc = heap_open(AttributeRelationId, RowExclusiveLock);
4794
4795 /*
4796 * Are we adding the column to a recursion child? If so, check whether to
4797 * merge with an existing definition for the column. If we do merge, we
4798 * must not recurse. Children will already have the column, and recursing
4799 * into them would mess up attinhcount.
4800 */
4801 if (colDef->inhcount > 0)
4802 {
4803 HeapTuple tuple;
4804
4805 /* Does child already have a column by this name? */
4806 tuple = SearchSysCacheCopyAttName(myrelid, colDef->colname);
4807 if (HeapTupleIsValid(tuple))
4808 {
4809 Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
4810 Oid ctypeId;
4811 int32 ctypmod;
4812 Oid ccollid;
4813
4814 /* Child column must match on type, typmod, and collation */
4815 typenameTypeIdAndMod(NULL, colDef->typeName, &ctypeId, &ctypmod);
4816 if (ctypeId != childatt->atttypid ||
4817 ctypmod != childatt->atttypmod)
4818 ereport(ERROR,
4819 (errcode(ERRCODE_DATATYPE_MISMATCH),
4820 errmsg("child table \"%s\" has different type for column \"%s\"",
4821 RelationGetRelationName(rel), colDef->colname)));
4822 ccollid = GetColumnDefCollation(NULL, colDef, ctypeId);
4823 if (ccollid != childatt->attcollation)
4824 ereport(ERROR,
4825 (errcode(ERRCODE_COLLATION_MISMATCH),
4826 errmsg("child table \"%s\" has different collation for column \"%s\"",
4827 RelationGetRelationName(rel), colDef->colname),
4828 errdetail("\"%s\" versus \"%s\"",
4829 get_collation_name(ccollid),
4830 get_collation_name(childatt->attcollation))));
4831
4832 /* If it's OID, child column must actually be OID */
4833 if (isOid && childatt->attnum != ObjectIdAttributeNumber)
4834 ereport(ERROR,
4835 (errcode(ERRCODE_DATATYPE_MISMATCH),
4836 errmsg("child table \"%s\" has a conflicting \"%s\" column",
4837 RelationGetRelationName(rel), colDef->colname)));
4838
4839 /* Bump the existing child att's inhcount */
4840 childatt->attinhcount++;
4841 simple_heap_update(attrdesc, &tuple->t_self, tuple);
4842 CatalogUpdateIndexes(attrdesc, tuple);
4843
4844 heap_freetuple(tuple);
4845
4846 /* Inform the user about the merge */
4847 ereport(NOTICE,
4848 (errmsg("merging definition of column \"%s\" for child \"%s\"",
4849 colDef->colname, RelationGetRelationName(rel))));
4850
4851 heap_close(attrdesc, RowExclusiveLock);
4852 return InvalidObjectAddress;
4853 }
4854 }
4855
4856 pgclass = heap_open(RelationRelationId, RowExclusiveLock);
4857
4858 reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
4859 if (!HeapTupleIsValid(reltup))
4860 elog(ERROR, "cache lookup failed for relation %u", myrelid);
4861 relkind = ((Form_pg_class) GETSTRUCT(reltup))->relkind;
4862
4863 /* skip if the name already exists and if_not_exists is true */
4864 if (!check_for_column_name_collision(rel, colDef->colname, if_not_exists))
4865 {
4866 heap_close(attrdesc, RowExclusiveLock);
4867 heap_freetuple(reltup);
4868 heap_close(pgclass, RowExclusiveLock);
4869 return InvalidObjectAddress;
4870 }
4871
4872 /* Determine the new attribute's number */
4873 if (isOid)
4874 newattnum = ObjectIdAttributeNumber;
4875 else
4876 {
4877 newattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts + 1;
4878 if (newattnum > MaxHeapAttributeNumber)
4879 ereport(ERROR,
4880 (errcode(ERRCODE_TOO_MANY_COLUMNS),
4881 errmsg("tables can have at most %d columns",
4882 MaxHeapAttributeNumber)));
4883 }
4884
4885 typeTuple = typenameType(NULL, colDef->typeName, &typmod);
4886 tform = (Form_pg_type) GETSTRUCT(typeTuple);
4887 typeOid = HeapTupleGetOid(typeTuple);
4888
4889 aclresult = pg_type_aclcheck(typeOid, GetUserId(), ACL_USAGE);
4890 if (aclresult != ACLCHECK_OK)
4891 aclcheck_error_type(aclresult, typeOid);
4892
4893 collOid = GetColumnDefCollation(NULL, colDef, typeOid);
4894
4895 /* make sure datatype is legal for a column */
4896 CheckAttributeType(colDef->colname, typeOid, collOid,
4897 list_make1_oid(rel->rd_rel->reltype),
4898 false);
4899
4900 /* construct new attribute's pg_attribute entry */
4901 attribute.attrelid = myrelid;
4902 namestrcpy(&(attribute.attname), colDef->colname);
4903 attribute.atttypid = typeOid;
4904 attribute.attstattarget = (newattnum > 0) ? -1 : 0;
4905 attribute.attlen = tform->typlen;
4906 attribute.attcacheoff = -1;
4907 attribute.atttypmod = typmod;
4908 attribute.attnum = newattnum;
4909 attribute.attbyval = tform->typbyval;
4910 attribute.attndims = list_length(colDef->typeName->arrayBounds);
4911 attribute.attstorage = tform->typstorage;
4912 attribute.attalign = tform->typalign;
4913 attribute.attnotnull = colDef->is_not_null;
4914 attribute.atthasdef = false;
4915 attribute.attisdropped = false;
4916 attribute.attislocal = colDef->is_local;
4917 attribute.attinhcount = colDef->inhcount;
4918 attribute.attcollation = collOid;
4919 /* attribute.attacl is handled by InsertPgAttributeTuple */
4920
4921 ReleaseSysCache(typeTuple);
4922
4923 InsertPgAttributeTuple(attrdesc, &attribute, NULL);
4924
4925 heap_close(attrdesc, RowExclusiveLock);
4926
4927 /*
4928 * Update pg_class tuple as appropriate
4929 */
4930 if (isOid)
4931 ((Form_pg_class) GETSTRUCT(reltup))->relhasoids = true;
4932 else
4933 ((Form_pg_class) GETSTRUCT(reltup))->relnatts = newattnum;
4934
4935 simple_heap_update(pgclass, &reltup->t_self, reltup);
4936
4937 /* keep catalog indexes current */
4938 CatalogUpdateIndexes(pgclass, reltup);
4939
4940 heap_freetuple(reltup);
4941
4942 /* Post creation hook for new attribute */
4943 InvokeObjectPostCreateHook(RelationRelationId, myrelid, newattnum);
4944
4945 heap_close(pgclass, RowExclusiveLock);
4946
4947 /* Make the attribute's catalog entry visible */
4948 CommandCounterIncrement();
4949
4950 /*
4951 * Store the DEFAULT, if any, in the catalogs
4952 */
4953 if (colDef->raw_default)
4954 {
4955 RawColumnDefault *rawEnt;
4956
4957 rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
4958 rawEnt->attnum = attribute.attnum;
4959 rawEnt->raw_default = copyObject(colDef->raw_default);
4960
4961 /*
4962 * This function is intended for CREATE TABLE, so it processes a
4963 * _list_ of defaults, but we just do one.
4964 */
4965 AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
4966 false, true, false);
4967
4968 /* Make the additional catalog changes visible */
4969 CommandCounterIncrement();
4970 }
4971
4972 /*
4973 * Tell Phase 3 to fill in the default expression, if there is one.
4974 *
4975 * If there is no default, Phase 3 doesn't have to do anything, because
4976 * that effectively means that the default is NULL. The heap tuple access
4977 * routines always check for attnum > # of attributes in tuple, and return
4978 * NULL if so, so without any modification of the tuple data we will get
4979 * the effect of NULL values in the new column.
4980 *
4981 * An exception occurs when the new column is of a domain type: the domain
4982 * might have a NOT NULL constraint, or a check constraint that indirectly
4983 * rejects nulls. If there are any domain constraints then we construct
4984 * an explicit NULL default value that will be passed through
4985 * CoerceToDomain processing. (This is a tad inefficient, since it causes
4986 * rewriting the table which we really don't have to do, but the present
4987 * design of domain processing doesn't offer any simple way of checking
4988 * the constraints more directly.)
4989 *
4990 * Note: we use build_column_default, and not just the cooked default
4991 * returned by AddRelationNewConstraints, so that the right thing happens
4992 * when a datatype's default applies.
4993 *
4994 * We skip this step completely for views and foreign tables. For a view,
4995 * we can only get here from CREATE OR REPLACE VIEW, which historically
4996 * doesn't set up defaults, not even for domain-typed columns. And in any
4997 * case we mustn't invoke Phase 3 on a view or foreign table, since they
4998 * have no storage.
4999 */
5000 if (relkind != RELKIND_VIEW && relkind != RELKIND_COMPOSITE_TYPE
5001 && relkind != RELKIND_FOREIGN_TABLE && attribute.attnum > 0)
5002 {
5003 defval = (Expr *) build_column_default(rel, attribute.attnum);
5004
5005 if (!defval && DomainHasConstraints(typeOid))
5006 {
5007 Oid baseTypeId;
5008 int32 baseTypeMod;
5009 Oid baseTypeColl;
5010
5011 baseTypeMod = typmod;
5012 baseTypeId = getBaseTypeAndTypmod(typeOid, &baseTypeMod);
5013 baseTypeColl = get_typcollation(baseTypeId);
5014 defval = (Expr *) makeNullConst(baseTypeId, baseTypeMod, baseTypeColl);
5015 defval = (Expr *) coerce_to_target_type(NULL,
5016 (Node *) defval,
5017 baseTypeId,
5018 typeOid,
5019 typmod,
5020 COERCION_ASSIGNMENT,
5021 COERCE_IMPLICIT_CAST,
5022 -1);
5023 if (defval == NULL) /* should not happen */
5024 elog(ERROR, "failed to coerce base type to domain");
5025 }
5026
5027 if (defval)
5028 {
5029 NewColumnValue *newval;
5030
5031 newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
5032 newval->attnum = attribute.attnum;
5033 newval->expr = expression_planner(defval);
5034
5035 tab->newvals = lappend(tab->newvals, newval);
5036 tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
5037 }
5038
5039 /*
5040 * If the new column is NOT NULL, tell Phase 3 it needs to test that.
5041 * (Note we don't do this for an OID column. OID will be marked not
5042 * null, but since it's filled specially, there's no need to test
5043 * anything.)
5044 */
5045 tab->new_notnull |= colDef->is_not_null;
5046 }
5047
5048 /*
5049 * If we are adding an OID column, we have to tell Phase 3 to rewrite the
5050 * table to fix that.
5051 */
5052 if (isOid)
5053 tab->rewrite |= AT_REWRITE_ALTER_OID;
5054
5055 /*
5056 * Add needed dependency entries for the new column.
5057 */
5058 add_column_datatype_dependency(myrelid, newattnum, attribute.atttypid);
5059 add_column_collation_dependency(myrelid, newattnum, attribute.attcollation);
5060
5061 /*
5062 * Propagate to children as appropriate. Unlike most other ALTER
5063 * routines, we have to do this one level of recursion at a time; we can't
5064 * use find_all_inheritors to do it in one pass.
5065 */
5066 children = find_inheritance_children(RelationGetRelid(rel), lockmode);
5067
5068 /*
5069 * If we are told not to recurse, there had better not be any child
5070 * tables; else the addition would put them out of step.
5071 */
5072 if (children && !recurse)
5073 ereport(ERROR,
5074 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
5075 errmsg("column must be added to child tables too")));
5076
5077 /* Children should see column as singly inherited */
5078 if (!recursing)
5079 {
5080 colDef = copyObject(colDef);
5081 colDef->inhcount = 1;
5082 colDef->is_local = false;
5083 }
5084
5085 foreach(child, children)
5086 {
5087 Oid childrelid = lfirst_oid(child);
5088 Relation childrel;
5089 AlteredTableInfo *childtab;
5090
5091 /* find_inheritance_children already got lock */
5092 childrel = heap_open(childrelid, NoLock);
5093 CheckTableNotInUse(childrel, "ALTER TABLE");
5094
5095 /* Find or create work queue entry for this table */
5096 childtab = ATGetQueueEntry(wqueue, childrel);
5097
5098 /* Recurse to child; return value is ignored */
5099 ATExecAddColumn(wqueue, childtab, childrel,
5100 colDef, isOid, recurse, true,
5101 if_not_exists, lockmode);
5102
5103 heap_close(childrel, NoLock);
5104 }
5105
5106 ObjectAddressSubSet(address, RelationRelationId, myrelid, newattnum);
5107 return address;
5108 }
5109
5110 /*
5111 * If a new or renamed column will collide with the name of an existing
5112 * column and if_not_exists is false then error out, else do nothing.
5113 */
5114 static bool
check_for_column_name_collision(Relation rel,const char * colname,bool if_not_exists)5115 check_for_column_name_collision(Relation rel, const char *colname,
5116 bool if_not_exists)
5117 {
5118 HeapTuple attTuple;
5119 int attnum;
5120
5121 /*
5122 * this test is deliberately not attisdropped-aware, since if one tries to
5123 * add a column matching a dropped column name, it's gonna fail anyway.
5124 */
5125 attTuple = SearchSysCache2(ATTNAME,
5126 ObjectIdGetDatum(RelationGetRelid(rel)),
5127 PointerGetDatum(colname));
5128 if (!HeapTupleIsValid(attTuple))
5129 return true;
5130
5131 attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum;
5132 ReleaseSysCache(attTuple);
5133
5134 /*
5135 * We throw a different error message for conflicts with system column
5136 * names, since they are normally not shown and the user might otherwise
5137 * be confused about the reason for the conflict.
5138 */
5139 if (attnum <= 0)
5140 ereport(ERROR,
5141 (errcode(ERRCODE_DUPLICATE_COLUMN),
5142 errmsg("column name \"%s\" conflicts with a system column name",
5143 colname)));
5144 else
5145 {
5146 if (if_not_exists)
5147 {
5148 ereport(NOTICE,
5149 (errcode(ERRCODE_DUPLICATE_COLUMN),
5150 errmsg("column \"%s\" of relation \"%s\" already exists, skipping",
5151 colname, RelationGetRelationName(rel))));
5152 return false;
5153 }
5154
5155 ereport(ERROR,
5156 (errcode(ERRCODE_DUPLICATE_COLUMN),
5157 errmsg("column \"%s\" of relation \"%s\" already exists",
5158 colname, RelationGetRelationName(rel))));
5159 }
5160
5161 return true;
5162 }
5163
5164 /*
5165 * Install a column's dependency on its datatype.
5166 */
5167 static void
add_column_datatype_dependency(Oid relid,int32 attnum,Oid typid)5168 add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid)
5169 {
5170 ObjectAddress myself,
5171 referenced;
5172
5173 myself.classId = RelationRelationId;
5174 myself.objectId = relid;
5175 myself.objectSubId = attnum;
5176 referenced.classId = TypeRelationId;
5177 referenced.objectId = typid;
5178 referenced.objectSubId = 0;
5179 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
5180 }
5181
5182 /*
5183 * Install a column's dependency on its collation.
5184 */
5185 static void
add_column_collation_dependency(Oid relid,int32 attnum,Oid collid)5186 add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
5187 {
5188 ObjectAddress myself,
5189 referenced;
5190
5191 /* We know the default collation is pinned, so don't bother recording it */
5192 if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
5193 {
5194 myself.classId = RelationRelationId;
5195 myself.objectId = relid;
5196 myself.objectSubId = attnum;
5197 referenced.classId = CollationRelationId;
5198 referenced.objectId = collid;
5199 referenced.objectSubId = 0;
5200 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
5201 }
5202 }
5203
5204 /*
5205 * ALTER TABLE SET WITH OIDS
5206 *
5207 * Basically this is an ADD COLUMN for the special OID column. We have
5208 * to cons up a ColumnDef node because the ADD COLUMN code needs one.
5209 */
5210 static void
ATPrepAddOids(List ** wqueue,Relation rel,bool recurse,AlterTableCmd * cmd,LOCKMODE lockmode)5211 ATPrepAddOids(List **wqueue, Relation rel, bool recurse, AlterTableCmd *cmd, LOCKMODE lockmode)
5212 {
5213 /* If we're recursing to a child table, the ColumnDef is already set up */
5214 if (cmd->def == NULL)
5215 {
5216 ColumnDef *cdef = makeNode(ColumnDef);
5217
5218 cdef->colname = pstrdup("oid");
5219 cdef->typeName = makeTypeNameFromOid(OIDOID, -1);
5220 cdef->inhcount = 0;
5221 cdef->is_local = true;
5222 cdef->is_not_null = true;
5223 cdef->storage = 0;
5224 cdef->location = -1;
5225 cmd->def = (Node *) cdef;
5226 }
5227 ATPrepAddColumn(wqueue, rel, recurse, false, false, cmd, lockmode);
5228
5229 if (recurse)
5230 cmd->subtype = AT_AddOidsRecurse;
5231 }
5232
5233 /*
5234 * ALTER TABLE ALTER COLUMN DROP NOT NULL
5235 *
5236 * Return the address of the modified column. If the column was already
5237 * nullable, InvalidObjectAddress is returned.
5238 */
5239 static ObjectAddress
ATExecDropNotNull(Relation rel,const char * colName,LOCKMODE lockmode)5240 ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
5241 {
5242 HeapTuple tuple;
5243 AttrNumber attnum;
5244 Relation attr_rel;
5245 List *indexoidlist;
5246 ListCell *indexoidscan;
5247 ObjectAddress address;
5248
5249 /*
5250 * lookup the attribute
5251 */
5252 attr_rel = heap_open(AttributeRelationId, RowExclusiveLock);
5253
5254 tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
5255
5256 if (!HeapTupleIsValid(tuple))
5257 ereport(ERROR,
5258 (errcode(ERRCODE_UNDEFINED_COLUMN),
5259 errmsg("column \"%s\" of relation \"%s\" does not exist",
5260 colName, RelationGetRelationName(rel))));
5261
5262 attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
5263
5264 /* Prevent them from altering a system attribute */
5265 if (attnum <= 0)
5266 ereport(ERROR,
5267 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5268 errmsg("cannot alter system column \"%s\"",
5269 colName)));
5270
5271 /*
5272 * Check that the attribute is not in a primary key
5273 *
5274 * Note: we'll throw error even if the pkey index is not valid.
5275 */
5276
5277 /* Loop over all indexes on the relation */
5278 indexoidlist = RelationGetIndexList(rel);
5279
5280 foreach(indexoidscan, indexoidlist)
5281 {
5282 Oid indexoid = lfirst_oid(indexoidscan);
5283 HeapTuple indexTuple;
5284 Form_pg_index indexStruct;
5285 int i;
5286
5287 indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
5288 if (!HeapTupleIsValid(indexTuple))
5289 elog(ERROR, "cache lookup failed for index %u", indexoid);
5290 indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
5291
5292 /* If the index is not a primary key, skip the check */
5293 if (indexStruct->indisprimary)
5294 {
5295 /*
5296 * Loop over each attribute in the primary key and see if it
5297 * matches the to-be-altered attribute
5298 */
5299 for (i = 0; i < indexStruct->indnatts; i++)
5300 {
5301 if (indexStruct->indkey.values[i] == attnum)
5302 ereport(ERROR,
5303 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
5304 errmsg("column \"%s\" is in a primary key",
5305 colName)));
5306 }
5307 }
5308
5309 ReleaseSysCache(indexTuple);
5310 }
5311
5312 list_free(indexoidlist);
5313
5314 /*
5315 * Okay, actually perform the catalog change ... if needed
5316 */
5317 if (((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
5318 {
5319 ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = FALSE;
5320
5321 simple_heap_update(attr_rel, &tuple->t_self, tuple);
5322
5323 /* keep the system catalog indexes current */
5324 CatalogUpdateIndexes(attr_rel, tuple);
5325
5326 ObjectAddressSubSet(address, RelationRelationId,
5327 RelationGetRelid(rel), attnum);
5328 }
5329 else
5330 address = InvalidObjectAddress;
5331
5332 InvokeObjectPostAlterHook(RelationRelationId,
5333 RelationGetRelid(rel), attnum);
5334
5335 heap_close(attr_rel, RowExclusiveLock);
5336
5337 return address;
5338 }
5339
5340 /*
5341 * ALTER TABLE ALTER COLUMN SET NOT NULL
5342 *
5343 * Return the address of the modified column. If the column was already NOT
5344 * NULL, InvalidObjectAddress is returned.
5345 */
5346 static ObjectAddress
ATExecSetNotNull(AlteredTableInfo * tab,Relation rel,const char * colName,LOCKMODE lockmode)5347 ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
5348 const char *colName, LOCKMODE lockmode)
5349 {
5350 HeapTuple tuple;
5351 AttrNumber attnum;
5352 Relation attr_rel;
5353 ObjectAddress address;
5354
5355 /*
5356 * lookup the attribute
5357 */
5358 attr_rel = heap_open(AttributeRelationId, RowExclusiveLock);
5359
5360 tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
5361
5362 if (!HeapTupleIsValid(tuple))
5363 ereport(ERROR,
5364 (errcode(ERRCODE_UNDEFINED_COLUMN),
5365 errmsg("column \"%s\" of relation \"%s\" does not exist",
5366 colName, RelationGetRelationName(rel))));
5367
5368 attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
5369
5370 /* Prevent them from altering a system attribute */
5371 if (attnum <= 0)
5372 ereport(ERROR,
5373 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5374 errmsg("cannot alter system column \"%s\"",
5375 colName)));
5376
5377 /*
5378 * Okay, actually perform the catalog change ... if needed
5379 */
5380 if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
5381 {
5382 ((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = TRUE;
5383
5384 simple_heap_update(attr_rel, &tuple->t_self, tuple);
5385
5386 /* keep the system catalog indexes current */
5387 CatalogUpdateIndexes(attr_rel, tuple);
5388
5389 /* Tell Phase 3 it needs to test the constraint */
5390 tab->new_notnull = true;
5391
5392 ObjectAddressSubSet(address, RelationRelationId,
5393 RelationGetRelid(rel), attnum);
5394 }
5395 else
5396 address = InvalidObjectAddress;
5397
5398 InvokeObjectPostAlterHook(RelationRelationId,
5399 RelationGetRelid(rel), attnum);
5400
5401 heap_close(attr_rel, RowExclusiveLock);
5402
5403 return address;
5404 }
5405
5406 /*
5407 * ALTER TABLE ALTER COLUMN SET/DROP DEFAULT
5408 *
5409 * Return the address of the affected column.
5410 */
5411 static ObjectAddress
ATExecColumnDefault(Relation rel,const char * colName,Node * newDefault,LOCKMODE lockmode)5412 ATExecColumnDefault(Relation rel, const char *colName,
5413 Node *newDefault, LOCKMODE lockmode)
5414 {
5415 AttrNumber attnum;
5416 ObjectAddress address;
5417
5418 /*
5419 * get the number of the attribute
5420 */
5421 attnum = get_attnum(RelationGetRelid(rel), colName);
5422 if (attnum == InvalidAttrNumber)
5423 ereport(ERROR,
5424 (errcode(ERRCODE_UNDEFINED_COLUMN),
5425 errmsg("column \"%s\" of relation \"%s\" does not exist",
5426 colName, RelationGetRelationName(rel))));
5427
5428 /* Prevent them from altering a system attribute */
5429 if (attnum <= 0)
5430 ereport(ERROR,
5431 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5432 errmsg("cannot alter system column \"%s\"",
5433 colName)));
5434
5435 /*
5436 * Remove any old default for the column. We use RESTRICT here for
5437 * safety, but at present we do not expect anything to depend on the
5438 * default.
5439 *
5440 * We treat removing the existing default as an internal operation when it
5441 * is preparatory to adding a new default, but as a user-initiated
5442 * operation when the user asked for a drop.
5443 */
5444 RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
5445 newDefault == NULL ? false : true);
5446
5447 if (newDefault)
5448 {
5449 /* SET DEFAULT */
5450 RawColumnDefault *rawEnt;
5451
5452 rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
5453 rawEnt->attnum = attnum;
5454 rawEnt->raw_default = newDefault;
5455
5456 /*
5457 * This function is intended for CREATE TABLE, so it processes a
5458 * _list_ of defaults, but we just do one.
5459 */
5460 AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
5461 false, true, false);
5462 }
5463
5464 ObjectAddressSubSet(address, RelationRelationId,
5465 RelationGetRelid(rel), attnum);
5466 return address;
5467 }
5468
5469 /*
5470 * ALTER TABLE ALTER COLUMN SET STATISTICS
5471 */
5472 static void
ATPrepSetStatistics(Relation rel,const char * colName,Node * newValue,LOCKMODE lockmode)5473 ATPrepSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
5474 {
5475 /*
5476 * We do our own permission checking because (a) we want to allow SET
5477 * STATISTICS on indexes (for expressional index columns), and (b) we want
5478 * to allow SET STATISTICS on system catalogs without requiring
5479 * allowSystemTableMods to be turned on.
5480 */
5481 if (rel->rd_rel->relkind != RELKIND_RELATION &&
5482 rel->rd_rel->relkind != RELKIND_MATVIEW &&
5483 rel->rd_rel->relkind != RELKIND_INDEX &&
5484 rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE)
5485 ereport(ERROR,
5486 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
5487 errmsg("\"%s\" is not a table, materialized view, index, or foreign table",
5488 RelationGetRelationName(rel))));
5489
5490 /* Permissions checks */
5491 if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
5492 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
5493 RelationGetRelationName(rel));
5494 }
5495
5496 /*
5497 * Return value is the address of the modified column
5498 */
5499 static ObjectAddress
ATExecSetStatistics(Relation rel,const char * colName,Node * newValue,LOCKMODE lockmode)5500 ATExecSetStatistics(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
5501 {
5502 int newtarget;
5503 Relation attrelation;
5504 HeapTuple tuple;
5505 Form_pg_attribute attrtuple;
5506 AttrNumber attnum;
5507 ObjectAddress address;
5508
5509 Assert(IsA(newValue, Integer));
5510 newtarget = intVal(newValue);
5511
5512 /*
5513 * Limit target to a sane range
5514 */
5515 if (newtarget < -1)
5516 {
5517 ereport(ERROR,
5518 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5519 errmsg("statistics target %d is too low",
5520 newtarget)));
5521 }
5522 else if (newtarget > 10000)
5523 {
5524 newtarget = 10000;
5525 ereport(WARNING,
5526 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5527 errmsg("lowering statistics target to %d",
5528 newtarget)));
5529 }
5530
5531 attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
5532
5533 tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
5534
5535 if (!HeapTupleIsValid(tuple))
5536 ereport(ERROR,
5537 (errcode(ERRCODE_UNDEFINED_COLUMN),
5538 errmsg("column \"%s\" of relation \"%s\" does not exist",
5539 colName, RelationGetRelationName(rel))));
5540 attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
5541
5542 attnum = attrtuple->attnum;
5543 if (attnum <= 0)
5544 ereport(ERROR,
5545 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5546 errmsg("cannot alter system column \"%s\"",
5547 colName)));
5548
5549 attrtuple->attstattarget = newtarget;
5550
5551 simple_heap_update(attrelation, &tuple->t_self, tuple);
5552
5553 /* keep system catalog indexes current */
5554 CatalogUpdateIndexes(attrelation, tuple);
5555
5556 InvokeObjectPostAlterHook(RelationRelationId,
5557 RelationGetRelid(rel),
5558 attrtuple->attnum);
5559 ObjectAddressSubSet(address, RelationRelationId,
5560 RelationGetRelid(rel), attnum);
5561 heap_freetuple(tuple);
5562
5563 heap_close(attrelation, RowExclusiveLock);
5564
5565 return address;
5566 }
5567
5568 /*
5569 * Return value is the address of the modified column
5570 */
5571 static ObjectAddress
ATExecSetOptions(Relation rel,const char * colName,Node * options,bool isReset,LOCKMODE lockmode)5572 ATExecSetOptions(Relation rel, const char *colName, Node *options,
5573 bool isReset, LOCKMODE lockmode)
5574 {
5575 Relation attrelation;
5576 HeapTuple tuple,
5577 newtuple;
5578 Form_pg_attribute attrtuple;
5579 AttrNumber attnum;
5580 Datum datum,
5581 newOptions;
5582 bool isnull;
5583 ObjectAddress address;
5584 Datum repl_val[Natts_pg_attribute];
5585 bool repl_null[Natts_pg_attribute];
5586 bool repl_repl[Natts_pg_attribute];
5587
5588 attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
5589
5590 tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
5591
5592 if (!HeapTupleIsValid(tuple))
5593 ereport(ERROR,
5594 (errcode(ERRCODE_UNDEFINED_COLUMN),
5595 errmsg("column \"%s\" of relation \"%s\" does not exist",
5596 colName, RelationGetRelationName(rel))));
5597 attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
5598
5599 attnum = attrtuple->attnum;
5600 if (attnum <= 0)
5601 ereport(ERROR,
5602 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5603 errmsg("cannot alter system column \"%s\"",
5604 colName)));
5605
5606 /* Generate new proposed attoptions (text array) */
5607 Assert(IsA(options, List));
5608 datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions,
5609 &isnull);
5610 newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
5611 (List *) options, NULL, NULL, false,
5612 isReset);
5613 /* Validate new options */
5614 (void) attribute_reloptions(newOptions, true);
5615
5616 /* Build new tuple. */
5617 memset(repl_null, false, sizeof(repl_null));
5618 memset(repl_repl, false, sizeof(repl_repl));
5619 if (newOptions != (Datum) 0)
5620 repl_val[Anum_pg_attribute_attoptions - 1] = newOptions;
5621 else
5622 repl_null[Anum_pg_attribute_attoptions - 1] = true;
5623 repl_repl[Anum_pg_attribute_attoptions - 1] = true;
5624 newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation),
5625 repl_val, repl_null, repl_repl);
5626
5627 /* Update system catalog. */
5628 simple_heap_update(attrelation, &newtuple->t_self, newtuple);
5629 CatalogUpdateIndexes(attrelation, newtuple);
5630
5631 InvokeObjectPostAlterHook(RelationRelationId,
5632 RelationGetRelid(rel),
5633 attrtuple->attnum);
5634 ObjectAddressSubSet(address, RelationRelationId,
5635 RelationGetRelid(rel), attnum);
5636
5637 heap_freetuple(newtuple);
5638
5639 ReleaseSysCache(tuple);
5640
5641 heap_close(attrelation, RowExclusiveLock);
5642
5643 return address;
5644 }
5645
5646 /*
5647 * ALTER TABLE ALTER COLUMN SET STORAGE
5648 *
5649 * Return value is the address of the modified column
5650 */
5651 static ObjectAddress
ATExecSetStorage(Relation rel,const char * colName,Node * newValue,LOCKMODE lockmode)5652 ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
5653 {
5654 char *storagemode;
5655 char newstorage;
5656 Relation attrelation;
5657 HeapTuple tuple;
5658 Form_pg_attribute attrtuple;
5659 AttrNumber attnum;
5660 ObjectAddress address;
5661
5662 Assert(IsA(newValue, String));
5663 storagemode = strVal(newValue);
5664
5665 if (pg_strcasecmp(storagemode, "plain") == 0)
5666 newstorage = 'p';
5667 else if (pg_strcasecmp(storagemode, "external") == 0)
5668 newstorage = 'e';
5669 else if (pg_strcasecmp(storagemode, "extended") == 0)
5670 newstorage = 'x';
5671 else if (pg_strcasecmp(storagemode, "main") == 0)
5672 newstorage = 'm';
5673 else
5674 {
5675 ereport(ERROR,
5676 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5677 errmsg("invalid storage type \"%s\"",
5678 storagemode)));
5679 newstorage = 0; /* keep compiler quiet */
5680 }
5681
5682 attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
5683
5684 tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
5685
5686 if (!HeapTupleIsValid(tuple))
5687 ereport(ERROR,
5688 (errcode(ERRCODE_UNDEFINED_COLUMN),
5689 errmsg("column \"%s\" of relation \"%s\" does not exist",
5690 colName, RelationGetRelationName(rel))));
5691 attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
5692
5693 attnum = attrtuple->attnum;
5694 if (attnum <= 0)
5695 ereport(ERROR,
5696 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5697 errmsg("cannot alter system column \"%s\"",
5698 colName)));
5699
5700 /*
5701 * safety check: do not allow toasted storage modes unless column datatype
5702 * is TOAST-aware.
5703 */
5704 if (newstorage == 'p' || TypeIsToastable(attrtuple->atttypid))
5705 attrtuple->attstorage = newstorage;
5706 else
5707 ereport(ERROR,
5708 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5709 errmsg("column data type %s can only have storage PLAIN",
5710 format_type_be(attrtuple->atttypid))));
5711
5712 simple_heap_update(attrelation, &tuple->t_self, tuple);
5713
5714 /* keep system catalog indexes current */
5715 CatalogUpdateIndexes(attrelation, tuple);
5716
5717 InvokeObjectPostAlterHook(RelationRelationId,
5718 RelationGetRelid(rel),
5719 attrtuple->attnum);
5720
5721 heap_freetuple(tuple);
5722
5723 heap_close(attrelation, RowExclusiveLock);
5724
5725 ObjectAddressSubSet(address, RelationRelationId,
5726 RelationGetRelid(rel), attnum);
5727 return address;
5728 }
5729
5730
5731 /*
5732 * ALTER TABLE DROP COLUMN
5733 *
5734 * DROP COLUMN cannot use the normal ALTER TABLE recursion mechanism,
5735 * because we have to decide at runtime whether to recurse or not depending
5736 * on whether attinhcount goes to zero or not. (We can't check this in a
5737 * static pre-pass because it won't handle multiple inheritance situations
5738 * correctly.)
5739 */
5740 static void
ATPrepDropColumn(List ** wqueue,Relation rel,bool recurse,bool recursing,AlterTableCmd * cmd,LOCKMODE lockmode)5741 ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
5742 AlterTableCmd *cmd, LOCKMODE lockmode)
5743 {
5744 if (rel->rd_rel->reloftype && !recursing)
5745 ereport(ERROR,
5746 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
5747 errmsg("cannot drop column from typed table")));
5748
5749 if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
5750 ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
5751
5752 if (recurse)
5753 cmd->subtype = AT_DropColumnRecurse;
5754 }
5755
5756 /*
5757 * Return value is the address of the dropped column.
5758 */
5759 static ObjectAddress
ATExecDropColumn(List ** wqueue,Relation rel,const char * colName,DropBehavior behavior,bool recurse,bool recursing,bool missing_ok,LOCKMODE lockmode)5760 ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
5761 DropBehavior behavior,
5762 bool recurse, bool recursing,
5763 bool missing_ok, LOCKMODE lockmode)
5764 {
5765 HeapTuple tuple;
5766 Form_pg_attribute targetatt;
5767 AttrNumber attnum;
5768 List *children;
5769 ObjectAddress object;
5770
5771 /* At top level, permission check was done in ATPrepCmd, else do it */
5772 if (recursing)
5773 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
5774
5775 /*
5776 * get the number of the attribute
5777 */
5778 tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
5779 if (!HeapTupleIsValid(tuple))
5780 {
5781 if (!missing_ok)
5782 {
5783 ereport(ERROR,
5784 (errcode(ERRCODE_UNDEFINED_COLUMN),
5785 errmsg("column \"%s\" of relation \"%s\" does not exist",
5786 colName, RelationGetRelationName(rel))));
5787 }
5788 else
5789 {
5790 ereport(NOTICE,
5791 (errmsg("column \"%s\" of relation \"%s\" does not exist, skipping",
5792 colName, RelationGetRelationName(rel))));
5793 return InvalidObjectAddress;
5794 }
5795 }
5796 targetatt = (Form_pg_attribute) GETSTRUCT(tuple);
5797
5798 attnum = targetatt->attnum;
5799
5800 /* Can't drop a system attribute, except OID */
5801 if (attnum <= 0 && attnum != ObjectIdAttributeNumber)
5802 ereport(ERROR,
5803 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
5804 errmsg("cannot drop system column \"%s\"",
5805 colName)));
5806
5807 /* Don't drop inherited columns */
5808 if (targetatt->attinhcount > 0 && !recursing)
5809 ereport(ERROR,
5810 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
5811 errmsg("cannot drop inherited column \"%s\"",
5812 colName)));
5813
5814 ReleaseSysCache(tuple);
5815
5816 /*
5817 * Propagate to children as appropriate. Unlike most other ALTER
5818 * routines, we have to do this one level of recursion at a time; we can't
5819 * use find_all_inheritors to do it in one pass.
5820 */
5821 children = find_inheritance_children(RelationGetRelid(rel), lockmode);
5822
5823 if (children)
5824 {
5825 Relation attr_rel;
5826 ListCell *child;
5827
5828 attr_rel = heap_open(AttributeRelationId, RowExclusiveLock);
5829 foreach(child, children)
5830 {
5831 Oid childrelid = lfirst_oid(child);
5832 Relation childrel;
5833 Form_pg_attribute childatt;
5834
5835 /* find_inheritance_children already got lock */
5836 childrel = heap_open(childrelid, NoLock);
5837 CheckTableNotInUse(childrel, "ALTER TABLE");
5838
5839 tuple = SearchSysCacheCopyAttName(childrelid, colName);
5840 if (!HeapTupleIsValid(tuple)) /* shouldn't happen */
5841 elog(ERROR, "cache lookup failed for attribute \"%s\" of relation %u",
5842 colName, childrelid);
5843 childatt = (Form_pg_attribute) GETSTRUCT(tuple);
5844
5845 if (childatt->attinhcount <= 0) /* shouldn't happen */
5846 elog(ERROR, "relation %u has non-inherited attribute \"%s\"",
5847 childrelid, colName);
5848
5849 if (recurse)
5850 {
5851 /*
5852 * If the child column has other definition sources, just
5853 * decrement its inheritance count; if not, recurse to delete
5854 * it.
5855 */
5856 if (childatt->attinhcount == 1 && !childatt->attislocal)
5857 {
5858 /* Time to delete this child column, too */
5859 ATExecDropColumn(wqueue, childrel, colName,
5860 behavior, true, true,
5861 false, lockmode);
5862 }
5863 else
5864 {
5865 /* Child column must survive my deletion */
5866 childatt->attinhcount--;
5867
5868 simple_heap_update(attr_rel, &tuple->t_self, tuple);
5869
5870 /* keep the system catalog indexes current */
5871 CatalogUpdateIndexes(attr_rel, tuple);
5872
5873 /* Make update visible */
5874 CommandCounterIncrement();
5875 }
5876 }
5877 else
5878 {
5879 /*
5880 * If we were told to drop ONLY in this table (no recursion),
5881 * we need to mark the inheritors' attributes as locally
5882 * defined rather than inherited.
5883 */
5884 childatt->attinhcount--;
5885 childatt->attislocal = true;
5886
5887 simple_heap_update(attr_rel, &tuple->t_self, tuple);
5888
5889 /* keep the system catalog indexes current */
5890 CatalogUpdateIndexes(attr_rel, tuple);
5891
5892 /* Make update visible */
5893 CommandCounterIncrement();
5894 }
5895
5896 heap_freetuple(tuple);
5897
5898 heap_close(childrel, NoLock);
5899 }
5900 heap_close(attr_rel, RowExclusiveLock);
5901 }
5902
5903 /*
5904 * Perform the actual column deletion
5905 */
5906 object.classId = RelationRelationId;
5907 object.objectId = RelationGetRelid(rel);
5908 object.objectSubId = attnum;
5909
5910 performDeletion(&object, behavior, 0);
5911
5912 /*
5913 * If we dropped the OID column, must adjust pg_class.relhasoids and tell
5914 * Phase 3 to physically get rid of the column. We formerly left the
5915 * column in place physically, but this caused subtle problems. See
5916 * http://archives.postgresql.org/pgsql-hackers/2009-02/msg00363.php
5917 */
5918 if (attnum == ObjectIdAttributeNumber)
5919 {
5920 Relation class_rel;
5921 Form_pg_class tuple_class;
5922 AlteredTableInfo *tab;
5923
5924 class_rel = heap_open(RelationRelationId, RowExclusiveLock);
5925
5926 tuple = SearchSysCacheCopy1(RELOID,
5927 ObjectIdGetDatum(RelationGetRelid(rel)));
5928 if (!HeapTupleIsValid(tuple))
5929 elog(ERROR, "cache lookup failed for relation %u",
5930 RelationGetRelid(rel));
5931 tuple_class = (Form_pg_class) GETSTRUCT(tuple);
5932
5933 tuple_class->relhasoids = false;
5934 simple_heap_update(class_rel, &tuple->t_self, tuple);
5935
5936 /* Keep the catalog indexes up to date */
5937 CatalogUpdateIndexes(class_rel, tuple);
5938
5939 heap_close(class_rel, RowExclusiveLock);
5940
5941 /* Find or create work queue entry for this table */
5942 tab = ATGetQueueEntry(wqueue, rel);
5943
5944 /* Tell Phase 3 to physically remove the OID column */
5945 tab->rewrite |= AT_REWRITE_ALTER_OID;
5946 }
5947
5948 return object;
5949 }
5950
5951 /*
5952 * ALTER TABLE ADD INDEX
5953 *
5954 * There is no such command in the grammar, but parse_utilcmd.c converts
5955 * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands. This lets
5956 * us schedule creation of the index at the appropriate time during ALTER.
5957 *
5958 * Return value is the address of the new index.
5959 */
5960 static ObjectAddress
ATExecAddIndex(AlteredTableInfo * tab,Relation rel,IndexStmt * stmt,bool is_rebuild,LOCKMODE lockmode)5961 ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
5962 IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode)
5963 {
5964 bool check_rights;
5965 bool skip_build;
5966 bool quiet;
5967 ObjectAddress address;
5968
5969 Assert(IsA(stmt, IndexStmt));
5970 Assert(!stmt->concurrent);
5971
5972 /* The IndexStmt has already been through transformIndexStmt */
5973 Assert(stmt->transformed);
5974
5975 /* suppress schema rights check when rebuilding existing index */
5976 check_rights = !is_rebuild;
5977 /* skip index build if phase 3 will do it or we're reusing an old one */
5978 skip_build = tab->rewrite > 0 || OidIsValid(stmt->oldNode);
5979 /* suppress notices when rebuilding existing index */
5980 quiet = is_rebuild;
5981
5982 address = DefineIndex(RelationGetRelid(rel),
5983 stmt,
5984 InvalidOid, /* no predefined OID */
5985 true, /* is_alter_table */
5986 check_rights,
5987 skip_build,
5988 quiet);
5989
5990 /*
5991 * If TryReuseIndex() stashed a relfilenode for us, we used it for the new
5992 * index instead of building from scratch. The DROP of the old edition of
5993 * this index will have scheduled the storage for deletion at commit, so
5994 * cancel that pending deletion.
5995 */
5996 if (OidIsValid(stmt->oldNode))
5997 {
5998 Relation irel = index_open(address.objectId, NoLock);
5999
6000 RelationPreserveStorage(irel->rd_node, true);
6001 index_close(irel, NoLock);
6002 }
6003
6004 return address;
6005 }
6006
6007 /*
6008 * ALTER TABLE ADD CONSTRAINT USING INDEX
6009 *
6010 * Returns the address of the new constraint.
6011 */
6012 static ObjectAddress
ATExecAddIndexConstraint(AlteredTableInfo * tab,Relation rel,IndexStmt * stmt,LOCKMODE lockmode)6013 ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
6014 IndexStmt *stmt, LOCKMODE lockmode)
6015 {
6016 Oid index_oid = stmt->indexOid;
6017 Relation indexRel;
6018 char *indexName;
6019 IndexInfo *indexInfo;
6020 char *constraintName;
6021 char constraintType;
6022 ObjectAddress address;
6023
6024 Assert(IsA(stmt, IndexStmt));
6025 Assert(OidIsValid(index_oid));
6026 Assert(stmt->isconstraint);
6027
6028 indexRel = index_open(index_oid, AccessShareLock);
6029
6030 indexName = pstrdup(RelationGetRelationName(indexRel));
6031
6032 indexInfo = BuildIndexInfo(indexRel);
6033
6034 /* this should have been checked at parse time */
6035 if (!indexInfo->ii_Unique)
6036 elog(ERROR, "index \"%s\" is not unique", indexName);
6037
6038 /*
6039 * Determine name to assign to constraint. We require a constraint to
6040 * have the same name as the underlying index; therefore, use the index's
6041 * existing name as the default constraint name, and if the user
6042 * explicitly gives some other name for the constraint, rename the index
6043 * to match.
6044 */
6045 constraintName = stmt->idxname;
6046 if (constraintName == NULL)
6047 constraintName = indexName;
6048 else if (strcmp(constraintName, indexName) != 0)
6049 {
6050 ereport(NOTICE,
6051 (errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"",
6052 indexName, constraintName)));
6053 RenameRelationInternal(index_oid, constraintName, false);
6054 }
6055
6056 /* Extra checks needed if making primary key */
6057 if (stmt->primary)
6058 index_check_primary_key(rel, indexInfo, true, stmt);
6059
6060 /* Note we currently don't support EXCLUSION constraints here */
6061 if (stmt->primary)
6062 constraintType = CONSTRAINT_PRIMARY;
6063 else
6064 constraintType = CONSTRAINT_UNIQUE;
6065
6066 /* Create the catalog entries for the constraint */
6067 address = index_constraint_create(rel,
6068 index_oid,
6069 indexInfo,
6070 constraintName,
6071 constraintType,
6072 stmt->deferrable,
6073 stmt->initdeferred,
6074 stmt->primary,
6075 true, /* update pg_index */
6076 true, /* remove old dependencies */
6077 allowSystemTableMods,
6078 false); /* is_internal */
6079
6080 index_close(indexRel, NoLock);
6081
6082 return address;
6083 }
6084
6085 /*
6086 * ALTER TABLE ADD CONSTRAINT
6087 *
6088 * Return value is the address of the new constraint; if no constraint was
6089 * added, InvalidObjectAddress is returned.
6090 */
6091 static ObjectAddress
ATExecAddConstraint(List ** wqueue,AlteredTableInfo * tab,Relation rel,Constraint * newConstraint,bool recurse,bool is_readd,LOCKMODE lockmode)6092 ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
6093 Constraint *newConstraint, bool recurse, bool is_readd,
6094 LOCKMODE lockmode)
6095 {
6096 ObjectAddress address = InvalidObjectAddress;
6097
6098 Assert(IsA(newConstraint, Constraint));
6099
6100 /*
6101 * Currently, we only expect to see CONSTR_CHECK and CONSTR_FOREIGN nodes
6102 * arriving here (see the preprocessing done in parse_utilcmd.c). Use a
6103 * switch anyway to make it easier to add more code later.
6104 */
6105 switch (newConstraint->contype)
6106 {
6107 case CONSTR_CHECK:
6108 address =
6109 ATAddCheckConstraint(wqueue, tab, rel,
6110 newConstraint, recurse, false, is_readd,
6111 lockmode);
6112 break;
6113
6114 case CONSTR_FOREIGN:
6115
6116 /*
6117 * Note that we currently never recurse for FK constraints, so the
6118 * "recurse" flag is silently ignored.
6119 *
6120 * Assign or validate constraint name
6121 */
6122 if (newConstraint->conname)
6123 {
6124 if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
6125 RelationGetRelid(rel),
6126 RelationGetNamespace(rel),
6127 newConstraint->conname))
6128 ereport(ERROR,
6129 (errcode(ERRCODE_DUPLICATE_OBJECT),
6130 errmsg("constraint \"%s\" for relation \"%s\" already exists",
6131 newConstraint->conname,
6132 RelationGetRelationName(rel))));
6133 }
6134 else
6135 newConstraint->conname =
6136 ChooseConstraintName(RelationGetRelationName(rel),
6137 strVal(linitial(newConstraint->fk_attrs)),
6138 "fkey",
6139 RelationGetNamespace(rel),
6140 NIL);
6141
6142 address = ATAddForeignKeyConstraint(tab, rel, newConstraint,
6143 lockmode);
6144 break;
6145
6146 default:
6147 elog(ERROR, "unrecognized constraint type: %d",
6148 (int) newConstraint->contype);
6149 }
6150
6151 return address;
6152 }
6153
6154 /*
6155 * Add a check constraint to a single table and its children. Returns the
6156 * address of the constraint added to the parent relation, if one gets added,
6157 * or InvalidObjectAddress otherwise.
6158 *
6159 * Subroutine for ATExecAddConstraint.
6160 *
6161 * We must recurse to child tables during execution, rather than using
6162 * ALTER TABLE's normal prep-time recursion. The reason is that all the
6163 * constraints *must* be given the same name, else they won't be seen as
6164 * related later. If the user didn't explicitly specify a name, then
6165 * AddRelationNewConstraints would normally assign different names to the
6166 * child constraints. To fix that, we must capture the name assigned at
6167 * the parent table and pass that down.
6168 */
6169 static ObjectAddress
ATAddCheckConstraint(List ** wqueue,AlteredTableInfo * tab,Relation rel,Constraint * constr,bool recurse,bool recursing,bool is_readd,LOCKMODE lockmode)6170 ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
6171 Constraint *constr, bool recurse, bool recursing,
6172 bool is_readd, LOCKMODE lockmode)
6173 {
6174 List *newcons;
6175 ListCell *lcon;
6176 List *children;
6177 ListCell *child;
6178 ObjectAddress address = InvalidObjectAddress;
6179
6180 /* At top level, permission check was done in ATPrepCmd, else do it */
6181 if (recursing)
6182 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
6183
6184 /*
6185 * Call AddRelationNewConstraints to do the work, making sure it works on
6186 * a copy of the Constraint so transformExpr can't modify the original. It
6187 * returns a list of cooked constraints.
6188 *
6189 * If the constraint ends up getting merged with a pre-existing one, it's
6190 * omitted from the returned list, which is what we want: we do not need
6191 * to do any validation work. That can only happen at child tables,
6192 * though, since we disallow merging at the top level.
6193 */
6194 newcons = AddRelationNewConstraints(rel, NIL,
6195 list_make1(copyObject(constr)),
6196 recursing | is_readd, /* allow_merge */
6197 !recursing, /* is_local */
6198 is_readd); /* is_internal */
6199
6200 /* we don't expect more than one constraint here */
6201 Assert(list_length(newcons) <= 1);
6202
6203 /* Add each to-be-validated constraint to Phase 3's queue */
6204 foreach(lcon, newcons)
6205 {
6206 CookedConstraint *ccon = (CookedConstraint *) lfirst(lcon);
6207
6208 if (!ccon->skip_validation)
6209 {
6210 NewConstraint *newcon;
6211
6212 newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
6213 newcon->name = ccon->name;
6214 newcon->contype = ccon->contype;
6215 /* ExecQual wants implicit-AND format */
6216 newcon->qual = (Node *) make_ands_implicit((Expr *) ccon->expr);
6217
6218 tab->constraints = lappend(tab->constraints, newcon);
6219 }
6220
6221 /* Save the actually assigned name if it was defaulted */
6222 if (constr->conname == NULL)
6223 constr->conname = ccon->name;
6224
6225 ObjectAddressSet(address, ConstraintRelationId, ccon->conoid);
6226 }
6227
6228 /* At this point we must have a locked-down name to use */
6229 Assert(constr->conname != NULL);
6230
6231 /* Advance command counter in case same table is visited multiple times */
6232 CommandCounterIncrement();
6233
6234 /*
6235 * If the constraint got merged with an existing constraint, we're done.
6236 * We mustn't recurse to child tables in this case, because they've
6237 * already got the constraint, and visiting them again would lead to an
6238 * incorrect value for coninhcount.
6239 */
6240 if (newcons == NIL)
6241 return address;
6242
6243 /*
6244 * If adding a NO INHERIT constraint, no need to find our children.
6245 */
6246 if (constr->is_no_inherit)
6247 return address;
6248
6249 /*
6250 * Propagate to children as appropriate. Unlike most other ALTER
6251 * routines, we have to do this one level of recursion at a time; we can't
6252 * use find_all_inheritors to do it in one pass.
6253 */
6254 children = find_inheritance_children(RelationGetRelid(rel), lockmode);
6255
6256 /*
6257 * Check if ONLY was specified with ALTER TABLE. If so, allow the
6258 * constraint creation only if there are no children currently. Error out
6259 * otherwise.
6260 */
6261 if (!recurse && children != NIL)
6262 ereport(ERROR,
6263 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
6264 errmsg("constraint must be added to child tables too")));
6265
6266 foreach(child, children)
6267 {
6268 Oid childrelid = lfirst_oid(child);
6269 Relation childrel;
6270 AlteredTableInfo *childtab;
6271
6272 /* find_inheritance_children already got lock */
6273 childrel = heap_open(childrelid, NoLock);
6274 CheckTableNotInUse(childrel, "ALTER TABLE");
6275
6276 /* Find or create work queue entry for this table */
6277 childtab = ATGetQueueEntry(wqueue, childrel);
6278
6279 /* Recurse to child */
6280 ATAddCheckConstraint(wqueue, childtab, childrel,
6281 constr, recurse, true, is_readd, lockmode);
6282
6283 heap_close(childrel, NoLock);
6284 }
6285
6286 return address;
6287 }
6288
6289 /*
6290 * Add a foreign-key constraint to a single table; return the new constraint's
6291 * address.
6292 *
6293 * Subroutine for ATExecAddConstraint. Must already hold exclusive
6294 * lock on the rel, and have done appropriate validity checks for it.
6295 * We do permissions checks here, however.
6296 */
6297 static ObjectAddress
ATAddForeignKeyConstraint(AlteredTableInfo * tab,Relation rel,Constraint * fkconstraint,LOCKMODE lockmode)6298 ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel,
6299 Constraint *fkconstraint, LOCKMODE lockmode)
6300 {
6301 Relation pkrel;
6302 int16 pkattnum[INDEX_MAX_KEYS];
6303 int16 fkattnum[INDEX_MAX_KEYS];
6304 Oid pktypoid[INDEX_MAX_KEYS];
6305 Oid fktypoid[INDEX_MAX_KEYS];
6306 Oid opclasses[INDEX_MAX_KEYS];
6307 Oid pfeqoperators[INDEX_MAX_KEYS];
6308 Oid ppeqoperators[INDEX_MAX_KEYS];
6309 Oid ffeqoperators[INDEX_MAX_KEYS];
6310 int i;
6311 int numfks,
6312 numpks;
6313 Oid indexOid;
6314 Oid constrOid;
6315 bool old_check_ok;
6316 ObjectAddress address;
6317 ListCell *old_pfeqop_item = list_head(fkconstraint->old_conpfeqop);
6318
6319 /*
6320 * Grab ShareRowExclusiveLock on the pk table, so that someone doesn't
6321 * delete rows out from under us.
6322 */
6323 if (OidIsValid(fkconstraint->old_pktable_oid))
6324 pkrel = heap_open(fkconstraint->old_pktable_oid, ShareRowExclusiveLock);
6325 else
6326 pkrel = heap_openrv(fkconstraint->pktable, ShareRowExclusiveLock);
6327
6328 /*
6329 * Validity checks (permission checks wait till we have the column
6330 * numbers)
6331 */
6332 if (pkrel->rd_rel->relkind != RELKIND_RELATION)
6333 ereport(ERROR,
6334 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
6335 errmsg("referenced relation \"%s\" is not a table",
6336 RelationGetRelationName(pkrel))));
6337
6338 if (!allowSystemTableMods && IsSystemRelation(pkrel))
6339 ereport(ERROR,
6340 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6341 errmsg("permission denied: \"%s\" is a system catalog",
6342 RelationGetRelationName(pkrel))));
6343
6344 /*
6345 * References from permanent or unlogged tables to temp tables, and from
6346 * permanent tables to unlogged tables, are disallowed because the
6347 * referenced data can vanish out from under us. References from temp
6348 * tables to any other table type are also disallowed, because other
6349 * backends might need to run the RI triggers on the perm table, but they
6350 * can't reliably see tuples in the local buffers of other backends.
6351 */
6352 switch (rel->rd_rel->relpersistence)
6353 {
6354 case RELPERSISTENCE_PERMANENT:
6355 if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT)
6356 ereport(ERROR,
6357 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
6358 errmsg("constraints on permanent tables may reference only permanent tables")));
6359 break;
6360 case RELPERSISTENCE_UNLOGGED:
6361 if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT
6362 && pkrel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED)
6363 ereport(ERROR,
6364 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
6365 errmsg("constraints on unlogged tables may reference only permanent or unlogged tables")));
6366 break;
6367 case RELPERSISTENCE_TEMP:
6368 if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
6369 ereport(ERROR,
6370 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
6371 errmsg("constraints on temporary tables may reference only temporary tables")));
6372 if (!pkrel->rd_islocaltemp || !rel->rd_islocaltemp)
6373 ereport(ERROR,
6374 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
6375 errmsg("constraints on temporary tables must involve temporary tables of this session")));
6376 break;
6377 }
6378
6379 /*
6380 * Look up the referencing attributes to make sure they exist, and record
6381 * their attnums and type OIDs.
6382 */
6383 MemSet(pkattnum, 0, sizeof(pkattnum));
6384 MemSet(fkattnum, 0, sizeof(fkattnum));
6385 MemSet(pktypoid, 0, sizeof(pktypoid));
6386 MemSet(fktypoid, 0, sizeof(fktypoid));
6387 MemSet(opclasses, 0, sizeof(opclasses));
6388 MemSet(pfeqoperators, 0, sizeof(pfeqoperators));
6389 MemSet(ppeqoperators, 0, sizeof(ppeqoperators));
6390 MemSet(ffeqoperators, 0, sizeof(ffeqoperators));
6391
6392 numfks = transformColumnNameList(RelationGetRelid(rel),
6393 fkconstraint->fk_attrs,
6394 fkattnum, fktypoid);
6395
6396 /*
6397 * If the attribute list for the referenced table was omitted, lookup the
6398 * definition of the primary key and use it. Otherwise, validate the
6399 * supplied attribute list. In either case, discover the index OID and
6400 * index opclasses, and the attnums and type OIDs of the attributes.
6401 */
6402 if (fkconstraint->pk_attrs == NIL)
6403 {
6404 numpks = transformFkeyGetPrimaryKey(pkrel, &indexOid,
6405 &fkconstraint->pk_attrs,
6406 pkattnum, pktypoid,
6407 opclasses);
6408 }
6409 else
6410 {
6411 numpks = transformColumnNameList(RelationGetRelid(pkrel),
6412 fkconstraint->pk_attrs,
6413 pkattnum, pktypoid);
6414 /* Look for an index matching the column list */
6415 indexOid = transformFkeyCheckAttrs(pkrel, numpks, pkattnum,
6416 opclasses);
6417 }
6418
6419 /*
6420 * Now we can check permissions.
6421 */
6422 checkFkeyPermissions(pkrel, pkattnum, numpks);
6423 checkFkeyPermissions(rel, fkattnum, numfks);
6424
6425 /*
6426 * Look up the equality operators to use in the constraint.
6427 *
6428 * Note that we have to be careful about the difference between the actual
6429 * PK column type and the opclass' declared input type, which might be
6430 * only binary-compatible with it. The declared opcintype is the right
6431 * thing to probe pg_amop with.
6432 */
6433 if (numfks != numpks)
6434 ereport(ERROR,
6435 (errcode(ERRCODE_INVALID_FOREIGN_KEY),
6436 errmsg("number of referencing and referenced columns for foreign key disagree")));
6437
6438 /*
6439 * On the strength of a previous constraint, we might avoid scanning
6440 * tables to validate this one. See below.
6441 */
6442 old_check_ok = (fkconstraint->old_conpfeqop != NIL);
6443 Assert(!old_check_ok || numfks == list_length(fkconstraint->old_conpfeqop));
6444
6445 for (i = 0; i < numpks; i++)
6446 {
6447 Oid pktype = pktypoid[i];
6448 Oid fktype = fktypoid[i];
6449 Oid fktyped;
6450 HeapTuple cla_ht;
6451 Form_pg_opclass cla_tup;
6452 Oid amid;
6453 Oid opfamily;
6454 Oid opcintype;
6455 Oid pfeqop;
6456 Oid ppeqop;
6457 Oid ffeqop;
6458 int16 eqstrategy;
6459 Oid pfeqop_right;
6460
6461 /* We need several fields out of the pg_opclass entry */
6462 cla_ht = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclasses[i]));
6463 if (!HeapTupleIsValid(cla_ht))
6464 elog(ERROR, "cache lookup failed for opclass %u", opclasses[i]);
6465 cla_tup = (Form_pg_opclass) GETSTRUCT(cla_ht);
6466 amid = cla_tup->opcmethod;
6467 opfamily = cla_tup->opcfamily;
6468 opcintype = cla_tup->opcintype;
6469 ReleaseSysCache(cla_ht);
6470
6471 /*
6472 * Check it's a btree; currently this can never fail since no other
6473 * index AMs support unique indexes. If we ever did have other types
6474 * of unique indexes, we'd need a way to determine which operator
6475 * strategy number is equality. (Is it reasonable to insist that
6476 * every such index AM use btree's number for equality?)
6477 */
6478 if (amid != BTREE_AM_OID)
6479 elog(ERROR, "only b-tree indexes are supported for foreign keys");
6480 eqstrategy = BTEqualStrategyNumber;
6481
6482 /*
6483 * There had better be a primary equality operator for the index.
6484 * We'll use it for PK = PK comparisons.
6485 */
6486 ppeqop = get_opfamily_member(opfamily, opcintype, opcintype,
6487 eqstrategy);
6488
6489 if (!OidIsValid(ppeqop))
6490 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
6491 eqstrategy, opcintype, opcintype, opfamily);
6492
6493 /*
6494 * Are there equality operators that take exactly the FK type? Assume
6495 * we should look through any domain here.
6496 */
6497 fktyped = getBaseType(fktype);
6498
6499 pfeqop = get_opfamily_member(opfamily, opcintype, fktyped,
6500 eqstrategy);
6501 if (OidIsValid(pfeqop))
6502 {
6503 pfeqop_right = fktyped;
6504 ffeqop = get_opfamily_member(opfamily, fktyped, fktyped,
6505 eqstrategy);
6506 }
6507 else
6508 {
6509 /* keep compiler quiet */
6510 pfeqop_right = InvalidOid;
6511 ffeqop = InvalidOid;
6512 }
6513
6514 if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
6515 {
6516 /*
6517 * Otherwise, look for an implicit cast from the FK type to the
6518 * opcintype, and if found, use the primary equality operator.
6519 * This is a bit tricky because opcintype might be a polymorphic
6520 * type such as ANYARRAY or ANYENUM; so what we have to test is
6521 * whether the two actual column types can be concurrently cast to
6522 * that type. (Otherwise, we'd fail to reject combinations such
6523 * as int[] and point[].)
6524 */
6525 Oid input_typeids[2];
6526 Oid target_typeids[2];
6527
6528 input_typeids[0] = pktype;
6529 input_typeids[1] = fktype;
6530 target_typeids[0] = opcintype;
6531 target_typeids[1] = opcintype;
6532 if (can_coerce_type(2, input_typeids, target_typeids,
6533 COERCION_IMPLICIT))
6534 {
6535 pfeqop = ffeqop = ppeqop;
6536 pfeqop_right = opcintype;
6537 }
6538 }
6539
6540 if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
6541 ereport(ERROR,
6542 (errcode(ERRCODE_DATATYPE_MISMATCH),
6543 errmsg("foreign key constraint \"%s\" "
6544 "cannot be implemented",
6545 fkconstraint->conname),
6546 errdetail("Key columns \"%s\" and \"%s\" "
6547 "are of incompatible types: %s and %s.",
6548 strVal(list_nth(fkconstraint->fk_attrs, i)),
6549 strVal(list_nth(fkconstraint->pk_attrs, i)),
6550 format_type_be(fktype),
6551 format_type_be(pktype))));
6552
6553 if (old_check_ok)
6554 {
6555 /*
6556 * When a pfeqop changes, revalidate the constraint. We could
6557 * permit intra-opfamily changes, but that adds subtle complexity
6558 * without any concrete benefit for core types. We need not
6559 * assess ppeqop or ffeqop, which RI_Initial_Check() does not use.
6560 */
6561 old_check_ok = (pfeqop == lfirst_oid(old_pfeqop_item));
6562 old_pfeqop_item = lnext(old_pfeqop_item);
6563 }
6564 if (old_check_ok)
6565 {
6566 Oid old_fktype;
6567 Oid new_fktype;
6568 CoercionPathType old_pathtype;
6569 CoercionPathType new_pathtype;
6570 Oid old_castfunc;
6571 Oid new_castfunc;
6572
6573 /*
6574 * Identify coercion pathways from each of the old and new FK-side
6575 * column types to the right (foreign) operand type of the pfeqop.
6576 * We may assume that pg_constraint.conkey is not changing.
6577 */
6578 old_fktype = tab->oldDesc->attrs[fkattnum[i] - 1]->atttypid;
6579 new_fktype = fktype;
6580 old_pathtype = findFkeyCast(pfeqop_right, old_fktype,
6581 &old_castfunc);
6582 new_pathtype = findFkeyCast(pfeqop_right, new_fktype,
6583 &new_castfunc);
6584
6585 /*
6586 * Upon a change to the cast from the FK column to its pfeqop
6587 * operand, revalidate the constraint. For this evaluation, a
6588 * binary coercion cast is equivalent to no cast at all. While
6589 * type implementors should design implicit casts with an eye
6590 * toward consistency of operations like equality, we cannot
6591 * assume here that they have done so.
6592 *
6593 * A function with a polymorphic argument could change behavior
6594 * arbitrarily in response to get_fn_expr_argtype(). Therefore,
6595 * when the cast destination is polymorphic, we only avoid
6596 * revalidation if the input type has not changed at all. Given
6597 * just the core data types and operator classes, this requirement
6598 * prevents no would-be optimizations.
6599 *
6600 * If the cast converts from a base type to a domain thereon, then
6601 * that domain type must be the opcintype of the unique index.
6602 * Necessarily, the primary key column must then be of the domain
6603 * type. Since the constraint was previously valid, all values on
6604 * the foreign side necessarily exist on the primary side and in
6605 * turn conform to the domain. Consequently, we need not treat
6606 * domains specially here.
6607 *
6608 * Since we require that all collations share the same notion of
6609 * equality (which they do, because texteq reduces to bitwise
6610 * equality), we don't compare collation here.
6611 *
6612 * We need not directly consider the PK type. It's necessarily
6613 * binary coercible to the opcintype of the unique index column,
6614 * and ri_triggers.c will only deal with PK datums in terms of
6615 * that opcintype. Changing the opcintype also changes pfeqop.
6616 */
6617 old_check_ok = (new_pathtype == old_pathtype &&
6618 new_castfunc == old_castfunc &&
6619 (!IsPolymorphicType(pfeqop_right) ||
6620 new_fktype == old_fktype));
6621 }
6622
6623 pfeqoperators[i] = pfeqop;
6624 ppeqoperators[i] = ppeqop;
6625 ffeqoperators[i] = ffeqop;
6626 }
6627
6628 /*
6629 * Record the FK constraint in pg_constraint.
6630 */
6631 constrOid = CreateConstraintEntry(fkconstraint->conname,
6632 RelationGetNamespace(rel),
6633 CONSTRAINT_FOREIGN,
6634 fkconstraint->deferrable,
6635 fkconstraint->initdeferred,
6636 fkconstraint->initially_valid,
6637 RelationGetRelid(rel),
6638 fkattnum,
6639 numfks,
6640 InvalidOid, /* not a domain
6641 * constraint */
6642 indexOid,
6643 RelationGetRelid(pkrel),
6644 pkattnum,
6645 pfeqoperators,
6646 ppeqoperators,
6647 ffeqoperators,
6648 numpks,
6649 fkconstraint->fk_upd_action,
6650 fkconstraint->fk_del_action,
6651 fkconstraint->fk_matchtype,
6652 NULL, /* no exclusion constraint */
6653 NULL, /* no check constraint */
6654 NULL,
6655 NULL,
6656 true, /* islocal */
6657 0, /* inhcount */
6658 true, /* isnoinherit */
6659 false); /* is_internal */
6660 ObjectAddressSet(address, ConstraintRelationId, constrOid);
6661
6662 /*
6663 * Create the triggers that will enforce the constraint.
6664 */
6665 createForeignKeyTriggers(rel, RelationGetRelid(pkrel), fkconstraint,
6666 constrOid, indexOid);
6667
6668 /*
6669 * Tell Phase 3 to check that the constraint is satisfied by existing
6670 * rows. We can skip this during table creation, when requested explicitly
6671 * by specifying NOT VALID in an ADD FOREIGN KEY command, and when we're
6672 * recreating a constraint following a SET DATA TYPE operation that did
6673 * not impugn its validity.
6674 */
6675 if (!old_check_ok && !fkconstraint->skip_validation)
6676 {
6677 NewConstraint *newcon;
6678
6679 newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
6680 newcon->name = fkconstraint->conname;
6681 newcon->contype = CONSTR_FOREIGN;
6682 newcon->refrelid = RelationGetRelid(pkrel);
6683 newcon->refindid = indexOid;
6684 newcon->conid = constrOid;
6685 newcon->qual = (Node *) fkconstraint;
6686
6687 tab->constraints = lappend(tab->constraints, newcon);
6688 }
6689
6690 /*
6691 * Close pk table, but keep lock until we've committed.
6692 */
6693 heap_close(pkrel, NoLock);
6694
6695 return address;
6696 }
6697
6698 /*
6699 * ALTER TABLE ALTER CONSTRAINT
6700 *
6701 * Update the attributes of a constraint.
6702 *
6703 * Currently only works for Foreign Key constraints.
6704 * Foreign keys do not inherit, so we purposely ignore the
6705 * recursion bit here, but we keep the API the same for when
6706 * other constraint types are supported.
6707 *
6708 * If the constraint is modified, returns its address; otherwise, return
6709 * InvalidObjectAddress.
6710 */
6711 static ObjectAddress
ATExecAlterConstraint(Relation rel,AlterTableCmd * cmd,bool recurse,bool recursing,LOCKMODE lockmode)6712 ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
6713 bool recurse, bool recursing, LOCKMODE lockmode)
6714 {
6715 Constraint *cmdcon;
6716 Relation conrel;
6717 SysScanDesc scan;
6718 ScanKeyData key;
6719 HeapTuple contuple;
6720 Form_pg_constraint currcon = NULL;
6721 bool found = false;
6722 ObjectAddress address;
6723
6724 Assert(IsA(cmd->def, Constraint));
6725 cmdcon = (Constraint *) cmd->def;
6726
6727 conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
6728
6729 /*
6730 * Find and check the target constraint
6731 */
6732 ScanKeyInit(&key,
6733 Anum_pg_constraint_conrelid,
6734 BTEqualStrategyNumber, F_OIDEQ,
6735 ObjectIdGetDatum(RelationGetRelid(rel)));
6736 scan = systable_beginscan(conrel, ConstraintRelidIndexId,
6737 true, NULL, 1, &key);
6738
6739 while (HeapTupleIsValid(contuple = systable_getnext(scan)))
6740 {
6741 currcon = (Form_pg_constraint) GETSTRUCT(contuple);
6742 if (strcmp(NameStr(currcon->conname), cmdcon->conname) == 0)
6743 {
6744 found = true;
6745 break;
6746 }
6747 }
6748
6749 if (!found)
6750 ereport(ERROR,
6751 (errcode(ERRCODE_UNDEFINED_OBJECT),
6752 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
6753 cmdcon->conname, RelationGetRelationName(rel))));
6754
6755 if (currcon->contype != CONSTRAINT_FOREIGN)
6756 ereport(ERROR,
6757 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
6758 errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint",
6759 cmdcon->conname, RelationGetRelationName(rel))));
6760
6761 if (currcon->condeferrable != cmdcon->deferrable ||
6762 currcon->condeferred != cmdcon->initdeferred)
6763 {
6764 HeapTuple copyTuple;
6765 HeapTuple tgtuple;
6766 Form_pg_constraint copy_con;
6767 List *otherrelids = NIL;
6768 ScanKeyData tgkey;
6769 SysScanDesc tgscan;
6770 Relation tgrel;
6771 ListCell *lc;
6772
6773 /*
6774 * Now update the catalog, while we have the door open.
6775 */
6776 copyTuple = heap_copytuple(contuple);
6777 copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
6778 copy_con->condeferrable = cmdcon->deferrable;
6779 copy_con->condeferred = cmdcon->initdeferred;
6780 simple_heap_update(conrel, ©Tuple->t_self, copyTuple);
6781 CatalogUpdateIndexes(conrel, copyTuple);
6782
6783 InvokeObjectPostAlterHook(ConstraintRelationId,
6784 HeapTupleGetOid(contuple), 0);
6785
6786 heap_freetuple(copyTuple);
6787
6788 /*
6789 * Now we need to update the multiple entries in pg_trigger that
6790 * implement the constraint.
6791 */
6792 tgrel = heap_open(TriggerRelationId, RowExclusiveLock);
6793
6794 ScanKeyInit(&tgkey,
6795 Anum_pg_trigger_tgconstraint,
6796 BTEqualStrategyNumber, F_OIDEQ,
6797 ObjectIdGetDatum(HeapTupleGetOid(contuple)));
6798
6799 tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
6800 NULL, 1, &tgkey);
6801
6802 while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
6803 {
6804 Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple);
6805 Form_pg_trigger copy_tg;
6806
6807 /*
6808 * Remember OIDs of other relation(s) involved in FK constraint.
6809 * (Note: it's likely that we could skip forcing a relcache inval
6810 * for other rels that don't have a trigger whose properties
6811 * change, but let's be conservative.)
6812 */
6813 if (tgform->tgrelid != RelationGetRelid(rel))
6814 otherrelids = list_append_unique_oid(otherrelids,
6815 tgform->tgrelid);
6816
6817 /*
6818 * Update deferrability of RI_FKey_noaction_del,
6819 * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd
6820 * triggers, but not others; see createForeignKeyTriggers and
6821 * CreateFKCheckTrigger.
6822 */
6823 if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL &&
6824 tgform->tgfoid != F_RI_FKEY_NOACTION_UPD &&
6825 tgform->tgfoid != F_RI_FKEY_CHECK_INS &&
6826 tgform->tgfoid != F_RI_FKEY_CHECK_UPD)
6827 continue;
6828
6829 copyTuple = heap_copytuple(tgtuple);
6830 copy_tg = (Form_pg_trigger) GETSTRUCT(copyTuple);
6831
6832 copy_tg->tgdeferrable = cmdcon->deferrable;
6833 copy_tg->tginitdeferred = cmdcon->initdeferred;
6834 simple_heap_update(tgrel, ©Tuple->t_self, copyTuple);
6835 CatalogUpdateIndexes(tgrel, copyTuple);
6836
6837 InvokeObjectPostAlterHook(TriggerRelationId,
6838 HeapTupleGetOid(tgtuple), 0);
6839
6840 heap_freetuple(copyTuple);
6841 }
6842
6843 systable_endscan(tgscan);
6844
6845 heap_close(tgrel, RowExclusiveLock);
6846
6847 /*
6848 * Invalidate relcache so that others see the new attributes. We must
6849 * inval both the named rel and any others having relevant triggers.
6850 * (At present there should always be exactly one other rel, but
6851 * there's no need to hard-wire such an assumption here.)
6852 */
6853 CacheInvalidateRelcache(rel);
6854 foreach(lc, otherrelids)
6855 {
6856 CacheInvalidateRelcacheByRelid(lfirst_oid(lc));
6857 }
6858
6859 ObjectAddressSet(address, ConstraintRelationId,
6860 HeapTupleGetOid(contuple));
6861 }
6862 else
6863 address = InvalidObjectAddress;
6864
6865 systable_endscan(scan);
6866
6867 heap_close(conrel, RowExclusiveLock);
6868
6869 return address;
6870 }
6871
6872 /*
6873 * ALTER TABLE VALIDATE CONSTRAINT
6874 *
6875 * XXX The reason we handle recursion here rather than at Phase 1 is because
6876 * there's no good way to skip recursing when handling foreign keys: there is
6877 * no need to lock children in that case, yet we wouldn't be able to avoid
6878 * doing so at that level.
6879 *
6880 * Return value is the address of the validated constraint. If the constraint
6881 * was already validated, InvalidObjectAddress is returned.
6882 */
6883 static ObjectAddress
ATExecValidateConstraint(List ** wqueue,Relation rel,char * constrName,bool recurse,bool recursing,LOCKMODE lockmode)6884 ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName,
6885 bool recurse, bool recursing, LOCKMODE lockmode)
6886 {
6887 Relation conrel;
6888 SysScanDesc scan;
6889 ScanKeyData key;
6890 HeapTuple tuple;
6891 Form_pg_constraint con = NULL;
6892 bool found = false;
6893 ObjectAddress address;
6894
6895 conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
6896
6897 /*
6898 * Find and check the target constraint
6899 */
6900 ScanKeyInit(&key,
6901 Anum_pg_constraint_conrelid,
6902 BTEqualStrategyNumber, F_OIDEQ,
6903 ObjectIdGetDatum(RelationGetRelid(rel)));
6904 scan = systable_beginscan(conrel, ConstraintRelidIndexId,
6905 true, NULL, 1, &key);
6906
6907 while (HeapTupleIsValid(tuple = systable_getnext(scan)))
6908 {
6909 con = (Form_pg_constraint) GETSTRUCT(tuple);
6910 if (strcmp(NameStr(con->conname), constrName) == 0)
6911 {
6912 found = true;
6913 break;
6914 }
6915 }
6916
6917 if (!found)
6918 ereport(ERROR,
6919 (errcode(ERRCODE_UNDEFINED_OBJECT),
6920 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
6921 constrName, RelationGetRelationName(rel))));
6922
6923 if (con->contype != CONSTRAINT_FOREIGN &&
6924 con->contype != CONSTRAINT_CHECK)
6925 ereport(ERROR,
6926 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
6927 errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key or check constraint",
6928 constrName, RelationGetRelationName(rel))));
6929
6930 if (!con->convalidated)
6931 {
6932 AlteredTableInfo *tab;
6933 HeapTuple copyTuple;
6934 Form_pg_constraint copy_con;
6935
6936 if (con->contype == CONSTRAINT_FOREIGN)
6937 {
6938 NewConstraint *newcon;
6939 Constraint *fkconstraint;
6940
6941 /* Queue validation for phase 3 */
6942 fkconstraint = makeNode(Constraint);
6943 /* for now this is all we need */
6944 fkconstraint->conname = constrName;
6945
6946 newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
6947 newcon->name = constrName;
6948 newcon->contype = CONSTR_FOREIGN;
6949 newcon->refrelid = con->confrelid;
6950 newcon->refindid = con->conindid;
6951 newcon->conid = HeapTupleGetOid(tuple);
6952 newcon->qual = (Node *) fkconstraint;
6953
6954 /* Find or create work queue entry for this table */
6955 tab = ATGetQueueEntry(wqueue, rel);
6956 tab->constraints = lappend(tab->constraints, newcon);
6957
6958 /*
6959 * Foreign keys do not inherit, so we purposely ignore the
6960 * recursion bit here
6961 */
6962 }
6963 else if (con->contype == CONSTRAINT_CHECK)
6964 {
6965 List *children = NIL;
6966 ListCell *child;
6967 NewConstraint *newcon;
6968 bool isnull;
6969 Datum val;
6970 char *conbin;
6971
6972 /*
6973 * If we're recursing, the parent has already done this, so skip
6974 * it. Also, if the constraint is a NO INHERIT constraint, we
6975 * shouldn't try to look for it in the children.
6976 */
6977 if (!recursing && !con->connoinherit)
6978 children = find_all_inheritors(RelationGetRelid(rel),
6979 lockmode, NULL);
6980
6981 /*
6982 * For CHECK constraints, we must ensure that we only mark the
6983 * constraint as validated on the parent if it's already validated
6984 * on the children.
6985 *
6986 * We recurse before validating on the parent, to reduce risk of
6987 * deadlocks.
6988 */
6989 foreach(child, children)
6990 {
6991 Oid childoid = lfirst_oid(child);
6992 Relation childrel;
6993
6994 if (childoid == RelationGetRelid(rel))
6995 continue;
6996
6997 /*
6998 * If we are told not to recurse, there had better not be any
6999 * child tables; else the addition would put them out of step.
7000 */
7001 if (!recurse)
7002 ereport(ERROR,
7003 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
7004 errmsg("constraint must be validated on child tables too")));
7005
7006 /* find_all_inheritors already got lock */
7007 childrel = heap_open(childoid, NoLock);
7008
7009 ATExecValidateConstraint(wqueue, childrel, constrName, false,
7010 true, lockmode);
7011 heap_close(childrel, NoLock);
7012 }
7013
7014 /* Queue validation for phase 3 */
7015 newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
7016 newcon->name = constrName;
7017 newcon->contype = CONSTR_CHECK;
7018 newcon->refrelid = InvalidOid;
7019 newcon->refindid = InvalidOid;
7020 newcon->conid = HeapTupleGetOid(tuple);
7021
7022 val = SysCacheGetAttr(CONSTROID, tuple,
7023 Anum_pg_constraint_conbin, &isnull);
7024 if (isnull)
7025 elog(ERROR, "null conbin for constraint %u",
7026 HeapTupleGetOid(tuple));
7027
7028 conbin = TextDatumGetCString(val);
7029 newcon->qual = (Node *) make_ands_implicit((Expr *) stringToNode(conbin));
7030
7031 /* Find or create work queue entry for this table */
7032 tab = ATGetQueueEntry(wqueue, rel);
7033 tab->constraints = lappend(tab->constraints, newcon);
7034
7035 /*
7036 * Invalidate relcache so that others see the new validated
7037 * constraint.
7038 */
7039 CacheInvalidateRelcache(rel);
7040 }
7041
7042 /*
7043 * Now update the catalog, while we have the door open.
7044 */
7045 copyTuple = heap_copytuple(tuple);
7046 copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
7047 copy_con->convalidated = true;
7048 simple_heap_update(conrel, ©Tuple->t_self, copyTuple);
7049 CatalogUpdateIndexes(conrel, copyTuple);
7050
7051 InvokeObjectPostAlterHook(ConstraintRelationId,
7052 HeapTupleGetOid(tuple), 0);
7053
7054 heap_freetuple(copyTuple);
7055
7056 ObjectAddressSet(address, ConstraintRelationId,
7057 HeapTupleGetOid(tuple));
7058 }
7059 else
7060 address = InvalidObjectAddress; /* already validated */
7061
7062 systable_endscan(scan);
7063
7064 heap_close(conrel, RowExclusiveLock);
7065
7066 return address;
7067 }
7068
7069
7070 /*
7071 * transformColumnNameList - transform list of column names
7072 *
7073 * Lookup each name and return its attnum and type OID
7074 */
7075 static int
transformColumnNameList(Oid relId,List * colList,int16 * attnums,Oid * atttypids)7076 transformColumnNameList(Oid relId, List *colList,
7077 int16 *attnums, Oid *atttypids)
7078 {
7079 ListCell *l;
7080 int attnum;
7081
7082 attnum = 0;
7083 foreach(l, colList)
7084 {
7085 char *attname = strVal(lfirst(l));
7086 HeapTuple atttuple;
7087
7088 atttuple = SearchSysCacheAttName(relId, attname);
7089 if (!HeapTupleIsValid(atttuple))
7090 ereport(ERROR,
7091 (errcode(ERRCODE_UNDEFINED_COLUMN),
7092 errmsg("column \"%s\" referenced in foreign key constraint does not exist",
7093 attname)));
7094 if (attnum >= INDEX_MAX_KEYS)
7095 ereport(ERROR,
7096 (errcode(ERRCODE_TOO_MANY_COLUMNS),
7097 errmsg("cannot have more than %d keys in a foreign key",
7098 INDEX_MAX_KEYS)));
7099 attnums[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->attnum;
7100 atttypids[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid;
7101 ReleaseSysCache(atttuple);
7102 attnum++;
7103 }
7104
7105 return attnum;
7106 }
7107
7108 /*
7109 * transformFkeyGetPrimaryKey -
7110 *
7111 * Look up the names, attnums, and types of the primary key attributes
7112 * for the pkrel. Also return the index OID and index opclasses of the
7113 * index supporting the primary key.
7114 *
7115 * All parameters except pkrel are output parameters. Also, the function
7116 * return value is the number of attributes in the primary key.
7117 *
7118 * Used when the column list in the REFERENCES specification is omitted.
7119 */
7120 static int
transformFkeyGetPrimaryKey(Relation pkrel,Oid * indexOid,List ** attnamelist,int16 * attnums,Oid * atttypids,Oid * opclasses)7121 transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
7122 List **attnamelist,
7123 int16 *attnums, Oid *atttypids,
7124 Oid *opclasses)
7125 {
7126 List *indexoidlist;
7127 ListCell *indexoidscan;
7128 HeapTuple indexTuple = NULL;
7129 Form_pg_index indexStruct = NULL;
7130 Datum indclassDatum;
7131 bool isnull;
7132 oidvector *indclass;
7133 int i;
7134
7135 /*
7136 * Get the list of index OIDs for the table from the relcache, and look up
7137 * each one in the pg_index syscache until we find one marked primary key
7138 * (hopefully there isn't more than one such). Insist it's valid, too.
7139 */
7140 *indexOid = InvalidOid;
7141
7142 indexoidlist = RelationGetIndexList(pkrel);
7143
7144 foreach(indexoidscan, indexoidlist)
7145 {
7146 Oid indexoid = lfirst_oid(indexoidscan);
7147
7148 indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
7149 if (!HeapTupleIsValid(indexTuple))
7150 elog(ERROR, "cache lookup failed for index %u", indexoid);
7151 indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
7152 if (indexStruct->indisprimary && IndexIsValid(indexStruct))
7153 {
7154 /*
7155 * Refuse to use a deferrable primary key. This is per SQL spec,
7156 * and there would be a lot of interesting semantic problems if we
7157 * tried to allow it.
7158 */
7159 if (!indexStruct->indimmediate)
7160 ereport(ERROR,
7161 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
7162 errmsg("cannot use a deferrable primary key for referenced table \"%s\"",
7163 RelationGetRelationName(pkrel))));
7164
7165 *indexOid = indexoid;
7166 break;
7167 }
7168 ReleaseSysCache(indexTuple);
7169 }
7170
7171 list_free(indexoidlist);
7172
7173 /*
7174 * Check that we found it
7175 */
7176 if (!OidIsValid(*indexOid))
7177 ereport(ERROR,
7178 (errcode(ERRCODE_UNDEFINED_OBJECT),
7179 errmsg("there is no primary key for referenced table \"%s\"",
7180 RelationGetRelationName(pkrel))));
7181
7182 /* Must get indclass the hard way */
7183 indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
7184 Anum_pg_index_indclass, &isnull);
7185 Assert(!isnull);
7186 indclass = (oidvector *) DatumGetPointer(indclassDatum);
7187
7188 /*
7189 * Now build the list of PK attributes from the indkey definition (we
7190 * assume a primary key cannot have expressional elements)
7191 */
7192 *attnamelist = NIL;
7193 for (i = 0; i < indexStruct->indnatts; i++)
7194 {
7195 int pkattno = indexStruct->indkey.values[i];
7196
7197 attnums[i] = pkattno;
7198 atttypids[i] = attnumTypeId(pkrel, pkattno);
7199 opclasses[i] = indclass->values[i];
7200 *attnamelist = lappend(*attnamelist,
7201 makeString(pstrdup(NameStr(*attnumAttName(pkrel, pkattno)))));
7202 }
7203
7204 ReleaseSysCache(indexTuple);
7205
7206 return i;
7207 }
7208
7209 /*
7210 * transformFkeyCheckAttrs -
7211 *
7212 * Make sure that the attributes of a referenced table belong to a unique
7213 * (or primary key) constraint. Return the OID of the index supporting
7214 * the constraint, as well as the opclasses associated with the index
7215 * columns.
7216 */
7217 static Oid
transformFkeyCheckAttrs(Relation pkrel,int numattrs,int16 * attnums,Oid * opclasses)7218 transformFkeyCheckAttrs(Relation pkrel,
7219 int numattrs, int16 *attnums,
7220 Oid *opclasses) /* output parameter */
7221 {
7222 Oid indexoid = InvalidOid;
7223 bool found = false;
7224 bool found_deferrable = false;
7225 List *indexoidlist;
7226 ListCell *indexoidscan;
7227 int i,
7228 j;
7229
7230 /*
7231 * Reject duplicate appearances of columns in the referenced-columns list.
7232 * Such a case is forbidden by the SQL standard, and even if we thought it
7233 * useful to allow it, there would be ambiguity about how to match the
7234 * list to unique indexes (in particular, it'd be unclear which index
7235 * opclass goes with which FK column).
7236 */
7237 for (i = 0; i < numattrs; i++)
7238 {
7239 for (j = i + 1; j < numattrs; j++)
7240 {
7241 if (attnums[i] == attnums[j])
7242 ereport(ERROR,
7243 (errcode(ERRCODE_INVALID_FOREIGN_KEY),
7244 errmsg("foreign key referenced-columns list must not contain duplicates")));
7245 }
7246 }
7247
7248 /*
7249 * Get the list of index OIDs for the table from the relcache, and look up
7250 * each one in the pg_index syscache, and match unique indexes to the list
7251 * of attnums we are given.
7252 */
7253 indexoidlist = RelationGetIndexList(pkrel);
7254
7255 foreach(indexoidscan, indexoidlist)
7256 {
7257 HeapTuple indexTuple;
7258 Form_pg_index indexStruct;
7259
7260 indexoid = lfirst_oid(indexoidscan);
7261 indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
7262 if (!HeapTupleIsValid(indexTuple))
7263 elog(ERROR, "cache lookup failed for index %u", indexoid);
7264 indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
7265
7266 /*
7267 * Must have the right number of columns; must be unique and not a
7268 * partial index; forget it if there are any expressions, too. Invalid
7269 * indexes are out as well.
7270 */
7271 if (indexStruct->indnatts == numattrs &&
7272 indexStruct->indisunique &&
7273 IndexIsValid(indexStruct) &&
7274 heap_attisnull(indexTuple, Anum_pg_index_indpred) &&
7275 heap_attisnull(indexTuple, Anum_pg_index_indexprs))
7276 {
7277 Datum indclassDatum;
7278 bool isnull;
7279 oidvector *indclass;
7280
7281 /* Must get indclass the hard way */
7282 indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
7283 Anum_pg_index_indclass, &isnull);
7284 Assert(!isnull);
7285 indclass = (oidvector *) DatumGetPointer(indclassDatum);
7286
7287 /*
7288 * The given attnum list may match the index columns in any order.
7289 * Check for a match, and extract the appropriate opclasses while
7290 * we're at it.
7291 *
7292 * We know that attnums[] is duplicate-free per the test at the
7293 * start of this function, and we checked above that the number of
7294 * index columns agrees, so if we find a match for each attnums[]
7295 * entry then we must have a one-to-one match in some order.
7296 */
7297 for (i = 0; i < numattrs; i++)
7298 {
7299 found = false;
7300 for (j = 0; j < numattrs; j++)
7301 {
7302 if (attnums[i] == indexStruct->indkey.values[j])
7303 {
7304 opclasses[i] = indclass->values[j];
7305 found = true;
7306 break;
7307 }
7308 }
7309 if (!found)
7310 break;
7311 }
7312
7313 /*
7314 * Refuse to use a deferrable unique/primary key. This is per SQL
7315 * spec, and there would be a lot of interesting semantic problems
7316 * if we tried to allow it.
7317 */
7318 if (found && !indexStruct->indimmediate)
7319 {
7320 /*
7321 * Remember that we found an otherwise matching index, so that
7322 * we can generate a more appropriate error message.
7323 */
7324 found_deferrable = true;
7325 found = false;
7326 }
7327 }
7328 ReleaseSysCache(indexTuple);
7329 if (found)
7330 break;
7331 }
7332
7333 if (!found)
7334 {
7335 if (found_deferrable)
7336 ereport(ERROR,
7337 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
7338 errmsg("cannot use a deferrable unique constraint for referenced table \"%s\"",
7339 RelationGetRelationName(pkrel))));
7340 else
7341 ereport(ERROR,
7342 (errcode(ERRCODE_INVALID_FOREIGN_KEY),
7343 errmsg("there is no unique constraint matching given keys for referenced table \"%s\"",
7344 RelationGetRelationName(pkrel))));
7345 }
7346
7347 list_free(indexoidlist);
7348
7349 return indexoid;
7350 }
7351
7352 /*
7353 * findFkeyCast -
7354 *
7355 * Wrapper around find_coercion_pathway() for ATAddForeignKeyConstraint().
7356 * Caller has equal regard for binary coercibility and for an exact match.
7357 */
7358 static CoercionPathType
findFkeyCast(Oid targetTypeId,Oid sourceTypeId,Oid * funcid)7359 findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid)
7360 {
7361 CoercionPathType ret;
7362
7363 if (targetTypeId == sourceTypeId)
7364 {
7365 ret = COERCION_PATH_RELABELTYPE;
7366 *funcid = InvalidOid;
7367 }
7368 else
7369 {
7370 ret = find_coercion_pathway(targetTypeId, sourceTypeId,
7371 COERCION_IMPLICIT, funcid);
7372 if (ret == COERCION_PATH_NONE)
7373 /* A previously-relied-upon cast is now gone. */
7374 elog(ERROR, "could not find cast from %u to %u",
7375 sourceTypeId, targetTypeId);
7376 }
7377
7378 return ret;
7379 }
7380
7381 /* Permissions checks for ADD FOREIGN KEY */
7382 static void
checkFkeyPermissions(Relation rel,int16 * attnums,int natts)7383 checkFkeyPermissions(Relation rel, int16 *attnums, int natts)
7384 {
7385 Oid roleid = GetUserId();
7386 AclResult aclresult;
7387 int i;
7388
7389 /* Okay if we have relation-level REFERENCES permission */
7390 aclresult = pg_class_aclcheck(RelationGetRelid(rel), roleid,
7391 ACL_REFERENCES);
7392 if (aclresult == ACLCHECK_OK)
7393 return;
7394 /* Else we must have REFERENCES on each column */
7395 for (i = 0; i < natts; i++)
7396 {
7397 aclresult = pg_attribute_aclcheck(RelationGetRelid(rel), attnums[i],
7398 roleid, ACL_REFERENCES);
7399 if (aclresult != ACLCHECK_OK)
7400 aclcheck_error(aclresult, ACL_KIND_CLASS,
7401 RelationGetRelationName(rel));
7402 }
7403 }
7404
7405 /*
7406 * Scan the existing rows in a table to verify they meet a proposed FK
7407 * constraint.
7408 *
7409 * Caller must have opened and locked both relations appropriately.
7410 */
7411 static void
validateForeignKeyConstraint(char * conname,Relation rel,Relation pkrel,Oid pkindOid,Oid constraintOid)7412 validateForeignKeyConstraint(char *conname,
7413 Relation rel,
7414 Relation pkrel,
7415 Oid pkindOid,
7416 Oid constraintOid)
7417 {
7418 HeapScanDesc scan;
7419 HeapTuple tuple;
7420 Trigger trig;
7421 Snapshot snapshot;
7422
7423 ereport(DEBUG1,
7424 (errmsg("validating foreign key constraint \"%s\"", conname)));
7425
7426 /*
7427 * Build a trigger call structure; we'll need it either way.
7428 */
7429 MemSet(&trig, 0, sizeof(trig));
7430 trig.tgoid = InvalidOid;
7431 trig.tgname = conname;
7432 trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
7433 trig.tgisinternal = TRUE;
7434 trig.tgconstrrelid = RelationGetRelid(pkrel);
7435 trig.tgconstrindid = pkindOid;
7436 trig.tgconstraint = constraintOid;
7437 trig.tgdeferrable = FALSE;
7438 trig.tginitdeferred = FALSE;
7439 /* we needn't fill in tgargs or tgqual */
7440
7441 /*
7442 * See if we can do it with a single LEFT JOIN query. A FALSE result
7443 * indicates we must proceed with the fire-the-trigger method.
7444 */
7445 if (RI_Initial_Check(&trig, rel, pkrel))
7446 return;
7447
7448 /*
7449 * Scan through each tuple, calling RI_FKey_check_ins (insert trigger) as
7450 * if that tuple had just been inserted. If any of those fail, it should
7451 * ereport(ERROR) and that's that.
7452 */
7453 snapshot = RegisterSnapshot(GetLatestSnapshot());
7454 scan = heap_beginscan(rel, snapshot, 0, NULL);
7455
7456 while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
7457 {
7458 FunctionCallInfoData fcinfo;
7459 TriggerData trigdata;
7460
7461 /*
7462 * Make a call to the trigger function
7463 *
7464 * No parameters are passed, but we do set a context
7465 */
7466 MemSet(&fcinfo, 0, sizeof(fcinfo));
7467
7468 /*
7469 * We assume RI_FKey_check_ins won't look at flinfo...
7470 */
7471 trigdata.type = T_TriggerData;
7472 trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW;
7473 trigdata.tg_relation = rel;
7474 trigdata.tg_trigtuple = tuple;
7475 trigdata.tg_newtuple = NULL;
7476 trigdata.tg_trigger = &trig;
7477 trigdata.tg_trigtuplebuf = scan->rs_cbuf;
7478 trigdata.tg_newtuplebuf = InvalidBuffer;
7479
7480 fcinfo.context = (Node *) &trigdata;
7481
7482 RI_FKey_check_ins(&fcinfo);
7483 }
7484
7485 heap_endscan(scan);
7486 UnregisterSnapshot(snapshot);
7487 }
7488
7489 static void
CreateFKCheckTrigger(Oid myRelOid,Oid refRelOid,Constraint * fkconstraint,Oid constraintOid,Oid indexOid,bool on_insert)7490 CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint,
7491 Oid constraintOid, Oid indexOid, bool on_insert)
7492 {
7493 CreateTrigStmt *fk_trigger;
7494
7495 /*
7496 * Note: for a self-referential FK (referencing and referenced tables are
7497 * the same), it is important that the ON UPDATE action fires before the
7498 * CHECK action, since both triggers will fire on the same row during an
7499 * UPDATE event; otherwise the CHECK trigger will be checking a non-final
7500 * state of the row. Triggers fire in name order, so we ensure this by
7501 * using names like "RI_ConstraintTrigger_a_NNNN" for the action triggers
7502 * and "RI_ConstraintTrigger_c_NNNN" for the check triggers.
7503 */
7504 fk_trigger = makeNode(CreateTrigStmt);
7505 fk_trigger->trigname = "RI_ConstraintTrigger_c";
7506 fk_trigger->relation = NULL;
7507 fk_trigger->row = true;
7508 fk_trigger->timing = TRIGGER_TYPE_AFTER;
7509
7510 /* Either ON INSERT or ON UPDATE */
7511 if (on_insert)
7512 {
7513 fk_trigger->funcname = SystemFuncName("RI_FKey_check_ins");
7514 fk_trigger->events = TRIGGER_TYPE_INSERT;
7515 }
7516 else
7517 {
7518 fk_trigger->funcname = SystemFuncName("RI_FKey_check_upd");
7519 fk_trigger->events = TRIGGER_TYPE_UPDATE;
7520 }
7521
7522 fk_trigger->columns = NIL;
7523 fk_trigger->whenClause = NULL;
7524 fk_trigger->isconstraint = true;
7525 fk_trigger->deferrable = fkconstraint->deferrable;
7526 fk_trigger->initdeferred = fkconstraint->initdeferred;
7527 fk_trigger->constrrel = NULL;
7528 fk_trigger->args = NIL;
7529
7530 (void) CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid, constraintOid,
7531 indexOid, true);
7532
7533 /* Make changes-so-far visible */
7534 CommandCounterIncrement();
7535 }
7536
7537 /*
7538 * Create the triggers that implement an FK constraint.
7539 *
7540 * NB: if you change any trigger properties here, see also
7541 * ATExecAlterConstraint.
7542 */
7543 static void
createForeignKeyTriggers(Relation rel,Oid refRelOid,Constraint * fkconstraint,Oid constraintOid,Oid indexOid)7544 createForeignKeyTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint,
7545 Oid constraintOid, Oid indexOid)
7546 {
7547 Oid myRelOid;
7548 CreateTrigStmt *fk_trigger;
7549
7550 myRelOid = RelationGetRelid(rel);
7551
7552 /* Make changes-so-far visible */
7553 CommandCounterIncrement();
7554
7555 /*
7556 * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
7557 * DELETE action on the referenced table.
7558 */
7559 fk_trigger = makeNode(CreateTrigStmt);
7560 fk_trigger->trigname = "RI_ConstraintTrigger_a";
7561 fk_trigger->relation = NULL;
7562 fk_trigger->row = true;
7563 fk_trigger->timing = TRIGGER_TYPE_AFTER;
7564 fk_trigger->events = TRIGGER_TYPE_DELETE;
7565 fk_trigger->columns = NIL;
7566 fk_trigger->whenClause = NULL;
7567 fk_trigger->isconstraint = true;
7568 fk_trigger->constrrel = NULL;
7569 switch (fkconstraint->fk_del_action)
7570 {
7571 case FKCONSTR_ACTION_NOACTION:
7572 fk_trigger->deferrable = fkconstraint->deferrable;
7573 fk_trigger->initdeferred = fkconstraint->initdeferred;
7574 fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_del");
7575 break;
7576 case FKCONSTR_ACTION_RESTRICT:
7577 fk_trigger->deferrable = false;
7578 fk_trigger->initdeferred = false;
7579 fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_del");
7580 break;
7581 case FKCONSTR_ACTION_CASCADE:
7582 fk_trigger->deferrable = false;
7583 fk_trigger->initdeferred = false;
7584 fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_del");
7585 break;
7586 case FKCONSTR_ACTION_SETNULL:
7587 fk_trigger->deferrable = false;
7588 fk_trigger->initdeferred = false;
7589 fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_del");
7590 break;
7591 case FKCONSTR_ACTION_SETDEFAULT:
7592 fk_trigger->deferrable = false;
7593 fk_trigger->initdeferred = false;
7594 fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_del");
7595 break;
7596 default:
7597 elog(ERROR, "unrecognized FK action type: %d",
7598 (int) fkconstraint->fk_del_action);
7599 break;
7600 }
7601 fk_trigger->args = NIL;
7602
7603 (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid,
7604 indexOid, true);
7605
7606 /* Make changes-so-far visible */
7607 CommandCounterIncrement();
7608
7609 /*
7610 * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
7611 * UPDATE action on the referenced table.
7612 */
7613 fk_trigger = makeNode(CreateTrigStmt);
7614 fk_trigger->trigname = "RI_ConstraintTrigger_a";
7615 fk_trigger->relation = NULL;
7616 fk_trigger->row = true;
7617 fk_trigger->timing = TRIGGER_TYPE_AFTER;
7618 fk_trigger->events = TRIGGER_TYPE_UPDATE;
7619 fk_trigger->columns = NIL;
7620 fk_trigger->whenClause = NULL;
7621 fk_trigger->isconstraint = true;
7622 fk_trigger->constrrel = NULL;
7623 switch (fkconstraint->fk_upd_action)
7624 {
7625 case FKCONSTR_ACTION_NOACTION:
7626 fk_trigger->deferrable = fkconstraint->deferrable;
7627 fk_trigger->initdeferred = fkconstraint->initdeferred;
7628 fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_upd");
7629 break;
7630 case FKCONSTR_ACTION_RESTRICT:
7631 fk_trigger->deferrable = false;
7632 fk_trigger->initdeferred = false;
7633 fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_upd");
7634 break;
7635 case FKCONSTR_ACTION_CASCADE:
7636 fk_trigger->deferrable = false;
7637 fk_trigger->initdeferred = false;
7638 fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_upd");
7639 break;
7640 case FKCONSTR_ACTION_SETNULL:
7641 fk_trigger->deferrable = false;
7642 fk_trigger->initdeferred = false;
7643 fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_upd");
7644 break;
7645 case FKCONSTR_ACTION_SETDEFAULT:
7646 fk_trigger->deferrable = false;
7647 fk_trigger->initdeferred = false;
7648 fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_upd");
7649 break;
7650 default:
7651 elog(ERROR, "unrecognized FK action type: %d",
7652 (int) fkconstraint->fk_upd_action);
7653 break;
7654 }
7655 fk_trigger->args = NIL;
7656
7657 (void) CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid,
7658 indexOid, true);
7659
7660 /* Make changes-so-far visible */
7661 CommandCounterIncrement();
7662
7663 /*
7664 * Build and execute CREATE CONSTRAINT TRIGGER statements for the CHECK
7665 * action for both INSERTs and UPDATEs on the referencing table.
7666 */
7667 CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid,
7668 indexOid, true);
7669 CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid,
7670 indexOid, false);
7671 }
7672
7673 /*
7674 * ALTER TABLE DROP CONSTRAINT
7675 *
7676 * Like DROP COLUMN, we can't use the normal ALTER TABLE recursion mechanism.
7677 */
7678 static void
ATExecDropConstraint(Relation rel,const char * constrName,DropBehavior behavior,bool recurse,bool recursing,bool missing_ok,LOCKMODE lockmode)7679 ATExecDropConstraint(Relation rel, const char *constrName,
7680 DropBehavior behavior,
7681 bool recurse, bool recursing,
7682 bool missing_ok, LOCKMODE lockmode)
7683 {
7684 List *children;
7685 ListCell *child;
7686 Relation conrel;
7687 Form_pg_constraint con;
7688 SysScanDesc scan;
7689 ScanKeyData key;
7690 HeapTuple tuple;
7691 bool found = false;
7692 bool is_no_inherit_constraint = false;
7693
7694 /* At top level, permission check was done in ATPrepCmd, else do it */
7695 if (recursing)
7696 ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
7697
7698 conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
7699
7700 /*
7701 * Find and drop the target constraint
7702 */
7703 ScanKeyInit(&key,
7704 Anum_pg_constraint_conrelid,
7705 BTEqualStrategyNumber, F_OIDEQ,
7706 ObjectIdGetDatum(RelationGetRelid(rel)));
7707 scan = systable_beginscan(conrel, ConstraintRelidIndexId,
7708 true, NULL, 1, &key);
7709
7710 while (HeapTupleIsValid(tuple = systable_getnext(scan)))
7711 {
7712 ObjectAddress conobj;
7713
7714 con = (Form_pg_constraint) GETSTRUCT(tuple);
7715
7716 if (strcmp(NameStr(con->conname), constrName) != 0)
7717 continue;
7718
7719 /* Don't drop inherited constraints */
7720 if (con->coninhcount > 0 && !recursing)
7721 ereport(ERROR,
7722 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
7723 errmsg("cannot drop inherited constraint \"%s\" of relation \"%s\"",
7724 constrName, RelationGetRelationName(rel))));
7725
7726 is_no_inherit_constraint = con->connoinherit;
7727
7728 /*
7729 * If it's a foreign-key constraint, we'd better lock the referenced
7730 * table and check that that's not in use, just as we've already done
7731 * for the constrained table (else we might, eg, be dropping a trigger
7732 * that has unfired events). But we can/must skip that in the
7733 * self-referential case.
7734 */
7735 if (con->contype == CONSTRAINT_FOREIGN &&
7736 con->confrelid != RelationGetRelid(rel))
7737 {
7738 Relation frel;
7739
7740 /* Must match lock taken by RemoveTriggerById: */
7741 frel = heap_open(con->confrelid, AccessExclusiveLock);
7742 CheckTableNotInUse(frel, "ALTER TABLE");
7743 heap_close(frel, NoLock);
7744 }
7745
7746 /*
7747 * Perform the actual constraint deletion
7748 */
7749 conobj.classId = ConstraintRelationId;
7750 conobj.objectId = HeapTupleGetOid(tuple);
7751 conobj.objectSubId = 0;
7752
7753 performDeletion(&conobj, behavior, 0);
7754
7755 found = true;
7756
7757 /* constraint found and dropped -- no need to keep looping */
7758 break;
7759 }
7760
7761 systable_endscan(scan);
7762
7763 if (!found)
7764 {
7765 if (!missing_ok)
7766 {
7767 ereport(ERROR,
7768 (errcode(ERRCODE_UNDEFINED_OBJECT),
7769 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
7770 constrName, RelationGetRelationName(rel))));
7771 }
7772 else
7773 {
7774 ereport(NOTICE,
7775 (errmsg("constraint \"%s\" of relation \"%s\" does not exist, skipping",
7776 constrName, RelationGetRelationName(rel))));
7777 heap_close(conrel, RowExclusiveLock);
7778 return;
7779 }
7780 }
7781
7782 /*
7783 * Propagate to children as appropriate. Unlike most other ALTER
7784 * routines, we have to do this one level of recursion at a time; we can't
7785 * use find_all_inheritors to do it in one pass.
7786 */
7787 if (!is_no_inherit_constraint)
7788 children = find_inheritance_children(RelationGetRelid(rel), lockmode);
7789 else
7790 children = NIL;
7791
7792 foreach(child, children)
7793 {
7794 Oid childrelid = lfirst_oid(child);
7795 Relation childrel;
7796 HeapTuple copy_tuple;
7797
7798 /* find_inheritance_children already got lock */
7799 childrel = heap_open(childrelid, NoLock);
7800 CheckTableNotInUse(childrel, "ALTER TABLE");
7801
7802 ScanKeyInit(&key,
7803 Anum_pg_constraint_conrelid,
7804 BTEqualStrategyNumber, F_OIDEQ,
7805 ObjectIdGetDatum(childrelid));
7806 scan = systable_beginscan(conrel, ConstraintRelidIndexId,
7807 true, NULL, 1, &key);
7808
7809 /* scan for matching tuple - there should only be one */
7810 while (HeapTupleIsValid(tuple = systable_getnext(scan)))
7811 {
7812 con = (Form_pg_constraint) GETSTRUCT(tuple);
7813
7814 /* Right now only CHECK constraints can be inherited */
7815 if (con->contype != CONSTRAINT_CHECK)
7816 continue;
7817
7818 if (strcmp(NameStr(con->conname), constrName) == 0)
7819 break;
7820 }
7821
7822 if (!HeapTupleIsValid(tuple))
7823 ereport(ERROR,
7824 (errcode(ERRCODE_UNDEFINED_OBJECT),
7825 errmsg("constraint \"%s\" of relation \"%s\" does not exist",
7826 constrName,
7827 RelationGetRelationName(childrel))));
7828
7829 copy_tuple = heap_copytuple(tuple);
7830
7831 systable_endscan(scan);
7832
7833 con = (Form_pg_constraint) GETSTRUCT(copy_tuple);
7834
7835 if (con->coninhcount <= 0) /* shouldn't happen */
7836 elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
7837 childrelid, constrName);
7838
7839 if (recurse)
7840 {
7841 /*
7842 * If the child constraint has other definition sources, just
7843 * decrement its inheritance count; if not, recurse to delete it.
7844 */
7845 if (con->coninhcount == 1 && !con->conislocal)
7846 {
7847 /* Time to delete this child constraint, too */
7848 ATExecDropConstraint(childrel, constrName, behavior,
7849 true, true,
7850 false, lockmode);
7851 }
7852 else
7853 {
7854 /* Child constraint must survive my deletion */
7855 con->coninhcount--;
7856 simple_heap_update(conrel, ©_tuple->t_self, copy_tuple);
7857 CatalogUpdateIndexes(conrel, copy_tuple);
7858
7859 /* Make update visible */
7860 CommandCounterIncrement();
7861 }
7862 }
7863 else
7864 {
7865 /*
7866 * If we were told to drop ONLY in this table (no recursion), we
7867 * need to mark the inheritors' constraints as locally defined
7868 * rather than inherited.
7869 */
7870 con->coninhcount--;
7871 con->conislocal = true;
7872
7873 simple_heap_update(conrel, ©_tuple->t_self, copy_tuple);
7874 CatalogUpdateIndexes(conrel, copy_tuple);
7875
7876 /* Make update visible */
7877 CommandCounterIncrement();
7878 }
7879
7880 heap_freetuple(copy_tuple);
7881
7882 heap_close(childrel, NoLock);
7883 }
7884
7885 heap_close(conrel, RowExclusiveLock);
7886 }
7887
7888 /*
7889 * ALTER COLUMN TYPE
7890 */
7891 static void
ATPrepAlterColumnType(List ** wqueue,AlteredTableInfo * tab,Relation rel,bool recurse,bool recursing,AlterTableCmd * cmd,LOCKMODE lockmode)7892 ATPrepAlterColumnType(List **wqueue,
7893 AlteredTableInfo *tab, Relation rel,
7894 bool recurse, bool recursing,
7895 AlterTableCmd *cmd, LOCKMODE lockmode)
7896 {
7897 char *colName = cmd->name;
7898 ColumnDef *def = (ColumnDef *) cmd->def;
7899 TypeName *typeName = def->typeName;
7900 Node *transform = def->cooked_default;
7901 HeapTuple tuple;
7902 Form_pg_attribute attTup;
7903 AttrNumber attnum;
7904 Oid targettype;
7905 int32 targettypmod;
7906 Oid targetcollid;
7907 NewColumnValue *newval;
7908 ParseState *pstate = make_parsestate(NULL);
7909 AclResult aclresult;
7910
7911 if (rel->rd_rel->reloftype && !recursing)
7912 ereport(ERROR,
7913 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
7914 errmsg("cannot alter column type of typed table")));
7915
7916 /* lookup the attribute so we can check inheritance status */
7917 tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
7918 if (!HeapTupleIsValid(tuple))
7919 ereport(ERROR,
7920 (errcode(ERRCODE_UNDEFINED_COLUMN),
7921 errmsg("column \"%s\" of relation \"%s\" does not exist",
7922 colName, RelationGetRelationName(rel))));
7923 attTup = (Form_pg_attribute) GETSTRUCT(tuple);
7924 attnum = attTup->attnum;
7925
7926 /* Can't alter a system attribute */
7927 if (attnum <= 0)
7928 ereport(ERROR,
7929 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7930 errmsg("cannot alter system column \"%s\"",
7931 colName)));
7932
7933 /*
7934 * Don't alter inherited columns. At outer level, there had better not be
7935 * any inherited definition; when recursing, we assume this was checked at
7936 * the parent level (see below).
7937 */
7938 if (attTup->attinhcount > 0 && !recursing)
7939 ereport(ERROR,
7940 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
7941 errmsg("cannot alter inherited column \"%s\"",
7942 colName)));
7943
7944 /* Look up the target type */
7945 typenameTypeIdAndMod(NULL, typeName, &targettype, &targettypmod);
7946
7947 aclresult = pg_type_aclcheck(targettype, GetUserId(), ACL_USAGE);
7948 if (aclresult != ACLCHECK_OK)
7949 aclcheck_error_type(aclresult, targettype);
7950
7951 /* And the collation */
7952 targetcollid = GetColumnDefCollation(NULL, def, targettype);
7953
7954 /* make sure datatype is legal for a column */
7955 CheckAttributeType(colName, targettype, targetcollid,
7956 list_make1_oid(rel->rd_rel->reltype),
7957 false);
7958
7959 if (tab->relkind == RELKIND_RELATION)
7960 {
7961 /*
7962 * Set up an expression to transform the old data value to the new
7963 * type. If a USING option was given, use the expression as
7964 * transformed by transformAlterTableStmt, else just take the old
7965 * value and try to coerce it. We do this first so that type
7966 * incompatibility can be detected before we waste effort, and because
7967 * we need the expression to be parsed against the original table row
7968 * type.
7969 */
7970 if (!transform)
7971 {
7972 transform = (Node *) makeVar(1, attnum,
7973 attTup->atttypid, attTup->atttypmod,
7974 attTup->attcollation,
7975 0);
7976 }
7977
7978 transform = coerce_to_target_type(pstate,
7979 transform, exprType(transform),
7980 targettype, targettypmod,
7981 COERCION_ASSIGNMENT,
7982 COERCE_IMPLICIT_CAST,
7983 -1);
7984 if (transform == NULL)
7985 {
7986 /* error text depends on whether USING was specified or not */
7987 if (def->cooked_default != NULL)
7988 ereport(ERROR,
7989 (errcode(ERRCODE_DATATYPE_MISMATCH),
7990 errmsg("result of USING clause for column \"%s\""
7991 " cannot be cast automatically to type %s",
7992 colName, format_type_be(targettype)),
7993 errhint("You might need to add an explicit cast.")));
7994 else
7995 ereport(ERROR,
7996 (errcode(ERRCODE_DATATYPE_MISMATCH),
7997 errmsg("column \"%s\" cannot be cast automatically to type %s",
7998 colName, format_type_be(targettype)),
7999 /* translator: USING is SQL, don't translate it */
8000 errhint("You might need to specify \"USING %s::%s\".",
8001 quote_identifier(colName),
8002 format_type_with_typemod(targettype,
8003 targettypmod))));
8004 }
8005
8006 /* Fix collations after all else */
8007 assign_expr_collations(pstate, transform);
8008
8009 /* Plan the expr now so we can accurately assess the need to rewrite. */
8010 transform = (Node *) expression_planner((Expr *) transform);
8011
8012 /*
8013 * Add a work queue item to make ATRewriteTable update the column
8014 * contents.
8015 */
8016 newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
8017 newval->attnum = attnum;
8018 newval->expr = (Expr *) transform;
8019
8020 tab->newvals = lappend(tab->newvals, newval);
8021 if (ATColumnChangeRequiresRewrite(transform, attnum))
8022 tab->rewrite |= AT_REWRITE_COLUMN_REWRITE;
8023 }
8024 else if (transform)
8025 ereport(ERROR,
8026 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
8027 errmsg("\"%s\" is not a table",
8028 RelationGetRelationName(rel))));
8029
8030 if (tab->relkind == RELKIND_COMPOSITE_TYPE ||
8031 tab->relkind == RELKIND_FOREIGN_TABLE)
8032 {
8033 /*
8034 * For composite types, do this check now. Tables will check it later
8035 * when the table is being rewritten.
8036 */
8037 find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
8038 }
8039
8040 ReleaseSysCache(tuple);
8041
8042 /*
8043 * Recurse manually by queueing a new command for each child, if
8044 * necessary. We cannot apply ATSimpleRecursion here because we need to
8045 * remap attribute numbers in the USING expression, if any.
8046 *
8047 * If we are told not to recurse, there had better not be any child
8048 * tables; else the alter would put them out of step.
8049 */
8050 if (recurse)
8051 {
8052 Oid relid = RelationGetRelid(rel);
8053 List *child_oids,
8054 *child_numparents;
8055 ListCell *lo,
8056 *li;
8057
8058 child_oids = find_all_inheritors(relid, lockmode,
8059 &child_numparents);
8060
8061 /*
8062 * find_all_inheritors does the recursive search of the inheritance
8063 * hierarchy, so all we have to do is process all of the relids in the
8064 * list that it returns.
8065 */
8066 forboth(lo, child_oids, li, child_numparents)
8067 {
8068 Oid childrelid = lfirst_oid(lo);
8069 int numparents = lfirst_int(li);
8070 Relation childrel;
8071 HeapTuple childtuple;
8072 Form_pg_attribute childattTup;
8073
8074 if (childrelid == relid)
8075 continue;
8076
8077 /* find_all_inheritors already got lock */
8078 childrel = relation_open(childrelid, NoLock);
8079 CheckTableNotInUse(childrel, "ALTER TABLE");
8080
8081 /*
8082 * Verify that the child doesn't have any inherited definitions of
8083 * this column that came from outside this inheritance hierarchy.
8084 * (renameatt makes a similar test, though in a different way
8085 * because of its different recursion mechanism.)
8086 */
8087 childtuple = SearchSysCacheAttName(RelationGetRelid(childrel),
8088 colName);
8089 if (!HeapTupleIsValid(childtuple))
8090 ereport(ERROR,
8091 (errcode(ERRCODE_UNDEFINED_COLUMN),
8092 errmsg("column \"%s\" of relation \"%s\" does not exist",
8093 colName, RelationGetRelationName(childrel))));
8094 childattTup = (Form_pg_attribute) GETSTRUCT(childtuple);
8095
8096 if (childattTup->attinhcount > numparents)
8097 ereport(ERROR,
8098 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
8099 errmsg("cannot alter inherited column \"%s\" of relation \"%s\"",
8100 colName, RelationGetRelationName(childrel))));
8101
8102 ReleaseSysCache(childtuple);
8103
8104 /*
8105 * Remap the attribute numbers. If no USING expression was
8106 * specified, there is no need for this step.
8107 */
8108 if (def->cooked_default)
8109 {
8110 AttrNumber *attmap;
8111 bool found_whole_row;
8112
8113 /* create a copy to scribble on */
8114 cmd = copyObject(cmd);
8115
8116 attmap = convert_tuples_by_name_map(RelationGetDescr(childrel),
8117 RelationGetDescr(rel),
8118 gettext_noop("could not convert row type"));
8119 ((ColumnDef *) cmd->def)->cooked_default =
8120 map_variable_attnos(def->cooked_default,
8121 1, 0,
8122 attmap, RelationGetDescr(rel)->natts,
8123 &found_whole_row);
8124 if (found_whole_row)
8125 ereport(ERROR,
8126 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8127 errmsg("cannot convert whole-row table reference"),
8128 errdetail("USING expression contains a whole-row table reference.")));
8129 pfree(attmap);
8130 }
8131 ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode);
8132 relation_close(childrel, NoLock);
8133 }
8134 }
8135 else if (!recursing &&
8136 find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL)
8137 ereport(ERROR,
8138 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
8139 errmsg("type of inherited column \"%s\" must be changed in child tables too",
8140 colName)));
8141
8142 if (tab->relkind == RELKIND_COMPOSITE_TYPE)
8143 ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
8144 }
8145
8146 /*
8147 * When the data type of a column is changed, a rewrite might not be required
8148 * if the new type is sufficiently identical to the old one, and the USING
8149 * clause isn't trying to insert some other value. It's safe to skip the
8150 * rewrite if the old type is binary coercible to the new type, or if the
8151 * new type is an unconstrained domain over the old type. In the case of a
8152 * constrained domain, we could get by with scanning the table and checking
8153 * the constraint rather than actually rewriting it, but we don't currently
8154 * try to do that.
8155 */
8156 static bool
ATColumnChangeRequiresRewrite(Node * expr,AttrNumber varattno)8157 ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno)
8158 {
8159 Assert(expr != NULL);
8160
8161 for (;;)
8162 {
8163 /* only one varno, so no need to check that */
8164 if (IsA(expr, Var) &&((Var *) expr)->varattno == varattno)
8165 return false;
8166 else if (IsA(expr, RelabelType))
8167 expr = (Node *) ((RelabelType *) expr)->arg;
8168 else if (IsA(expr, CoerceToDomain))
8169 {
8170 CoerceToDomain *d = (CoerceToDomain *) expr;
8171
8172 if (DomainHasConstraints(d->resulttype))
8173 return true;
8174 expr = (Node *) d->arg;
8175 }
8176 else
8177 return true;
8178 }
8179 }
8180
8181 /*
8182 * ALTER COLUMN .. SET DATA TYPE
8183 *
8184 * Return the address of the modified column.
8185 */
8186 static ObjectAddress
ATExecAlterColumnType(AlteredTableInfo * tab,Relation rel,AlterTableCmd * cmd,LOCKMODE lockmode)8187 ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
8188 AlterTableCmd *cmd, LOCKMODE lockmode)
8189 {
8190 char *colName = cmd->name;
8191 ColumnDef *def = (ColumnDef *) cmd->def;
8192 TypeName *typeName = def->typeName;
8193 HeapTuple heapTup;
8194 Form_pg_attribute attTup;
8195 AttrNumber attnum;
8196 HeapTuple typeTuple;
8197 Form_pg_type tform;
8198 Oid targettype;
8199 int32 targettypmod;
8200 Oid targetcollid;
8201 Node *defaultexpr;
8202 Relation attrelation;
8203 Relation depRel;
8204 ScanKeyData key[3];
8205 SysScanDesc scan;
8206 HeapTuple depTup;
8207 ObjectAddress address;
8208
8209 attrelation = heap_open(AttributeRelationId, RowExclusiveLock);
8210
8211 /* Look up the target column */
8212 heapTup = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
8213 if (!HeapTupleIsValid(heapTup)) /* shouldn't happen */
8214 ereport(ERROR,
8215 (errcode(ERRCODE_UNDEFINED_COLUMN),
8216 errmsg("column \"%s\" of relation \"%s\" does not exist",
8217 colName, RelationGetRelationName(rel))));
8218 attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
8219 attnum = attTup->attnum;
8220
8221 /* Check for multiple ALTER TYPE on same column --- can't cope */
8222 if (attTup->atttypid != tab->oldDesc->attrs[attnum - 1]->atttypid ||
8223 attTup->atttypmod != tab->oldDesc->attrs[attnum - 1]->atttypmod)
8224 ereport(ERROR,
8225 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8226 errmsg("cannot alter type of column \"%s\" twice",
8227 colName)));
8228
8229 /* Look up the target type (should not fail, since prep found it) */
8230 typeTuple = typenameType(NULL, typeName, &targettypmod);
8231 tform = (Form_pg_type) GETSTRUCT(typeTuple);
8232 targettype = HeapTupleGetOid(typeTuple);
8233 /* And the collation */
8234 targetcollid = GetColumnDefCollation(NULL, def, targettype);
8235
8236 /*
8237 * If there is a default expression for the column, get it and ensure we
8238 * can coerce it to the new datatype. (We must do this before changing
8239 * the column type, because build_column_default itself will try to
8240 * coerce, and will not issue the error message we want if it fails.)
8241 *
8242 * We remove any implicit coercion steps at the top level of the old
8243 * default expression; this has been agreed to satisfy the principle of
8244 * least surprise. (The conversion to the new column type should act like
8245 * it started from what the user sees as the stored expression, and the
8246 * implicit coercions aren't going to be shown.)
8247 */
8248 if (attTup->atthasdef)
8249 {
8250 defaultexpr = build_column_default(rel, attnum);
8251 Assert(defaultexpr);
8252 defaultexpr = strip_implicit_coercions(defaultexpr);
8253 defaultexpr = coerce_to_target_type(NULL, /* no UNKNOWN params */
8254 defaultexpr, exprType(defaultexpr),
8255 targettype, targettypmod,
8256 COERCION_ASSIGNMENT,
8257 COERCE_IMPLICIT_CAST,
8258 -1);
8259 if (defaultexpr == NULL)
8260 ereport(ERROR,
8261 (errcode(ERRCODE_DATATYPE_MISMATCH),
8262 errmsg("default for column \"%s\" cannot be cast automatically to type %s",
8263 colName, format_type_be(targettype))));
8264 }
8265 else
8266 defaultexpr = NULL;
8267
8268 /*
8269 * Find everything that depends on the column (constraints, indexes, etc),
8270 * and record enough information to let us recreate the objects.
8271 *
8272 * The actual recreation does not happen here, but only after we have
8273 * performed all the individual ALTER TYPE operations. We have to save
8274 * the info before executing ALTER TYPE, though, else the deparser will
8275 * get confused.
8276 */
8277 depRel = heap_open(DependRelationId, RowExclusiveLock);
8278
8279 ScanKeyInit(&key[0],
8280 Anum_pg_depend_refclassid,
8281 BTEqualStrategyNumber, F_OIDEQ,
8282 ObjectIdGetDatum(RelationRelationId));
8283 ScanKeyInit(&key[1],
8284 Anum_pg_depend_refobjid,
8285 BTEqualStrategyNumber, F_OIDEQ,
8286 ObjectIdGetDatum(RelationGetRelid(rel)));
8287 ScanKeyInit(&key[2],
8288 Anum_pg_depend_refobjsubid,
8289 BTEqualStrategyNumber, F_INT4EQ,
8290 Int32GetDatum((int32) attnum));
8291
8292 scan = systable_beginscan(depRel, DependReferenceIndexId, true,
8293 NULL, 3, key);
8294
8295 while (HeapTupleIsValid(depTup = systable_getnext(scan)))
8296 {
8297 Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
8298 ObjectAddress foundObject;
8299
8300 /* We don't expect any PIN dependencies on columns */
8301 if (foundDep->deptype == DEPENDENCY_PIN)
8302 elog(ERROR, "cannot alter type of a pinned column");
8303
8304 foundObject.classId = foundDep->classid;
8305 foundObject.objectId = foundDep->objid;
8306 foundObject.objectSubId = foundDep->objsubid;
8307
8308 switch (getObjectClass(&foundObject))
8309 {
8310 case OCLASS_CLASS:
8311 {
8312 char relKind = get_rel_relkind(foundObject.objectId);
8313
8314 if (relKind == RELKIND_INDEX)
8315 {
8316 Assert(foundObject.objectSubId == 0);
8317 RememberIndexForRebuilding(foundObject.objectId, tab);
8318 }
8319 else if (relKind == RELKIND_SEQUENCE)
8320 {
8321 /*
8322 * This must be a SERIAL column's sequence. We need
8323 * not do anything to it.
8324 */
8325 Assert(foundObject.objectSubId == 0);
8326 }
8327 else
8328 {
8329 /* Not expecting any other direct dependencies... */
8330 elog(ERROR, "unexpected object depending on column: %s",
8331 getObjectDescription(&foundObject));
8332 }
8333 break;
8334 }
8335
8336 case OCLASS_CONSTRAINT:
8337 Assert(foundObject.objectSubId == 0);
8338 RememberConstraintForRebuilding(foundObject.objectId, tab,
8339 foundDep->deptype);
8340 break;
8341
8342 case OCLASS_REWRITE:
8343 /* XXX someday see if we can cope with revising views */
8344 ereport(ERROR,
8345 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8346 errmsg("cannot alter type of a column used by a view or rule"),
8347 errdetail("%s depends on column \"%s\"",
8348 getObjectDescription(&foundObject),
8349 colName)));
8350 break;
8351
8352 case OCLASS_TRIGGER:
8353
8354 /*
8355 * A trigger can depend on a column because the column is
8356 * specified as an update target, or because the column is
8357 * used in the trigger's WHEN condition. The first case would
8358 * not require any extra work, but the second case would
8359 * require updating the WHEN expression, which will take a
8360 * significant amount of new code. Since we can't easily tell
8361 * which case applies, we punt for both. FIXME someday.
8362 */
8363 ereport(ERROR,
8364 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8365 errmsg("cannot alter type of a column used in a trigger definition"),
8366 errdetail("%s depends on column \"%s\"",
8367 getObjectDescription(&foundObject),
8368 colName)));
8369 break;
8370
8371 case OCLASS_POLICY:
8372
8373 /*
8374 * A policy can depend on a column because the column is
8375 * specified in the policy's USING or WITH CHECK qual
8376 * expressions. It might be possible to rewrite and recheck
8377 * the policy expression, but punt for now. It's certainly
8378 * easy enough to remove and recreate the policy; still, FIXME
8379 * someday.
8380 */
8381 ereport(ERROR,
8382 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8383 errmsg("cannot alter type of a column used in a policy definition"),
8384 errdetail("%s depends on column \"%s\"",
8385 getObjectDescription(&foundObject),
8386 colName)));
8387 break;
8388
8389 case OCLASS_DEFAULT:
8390
8391 /*
8392 * Ignore the column's default expression, since we will fix
8393 * it below.
8394 */
8395 Assert(defaultexpr);
8396 break;
8397
8398 case OCLASS_PROC:
8399 case OCLASS_TYPE:
8400 case OCLASS_CAST:
8401 case OCLASS_COLLATION:
8402 case OCLASS_CONVERSION:
8403 case OCLASS_LANGUAGE:
8404 case OCLASS_LARGEOBJECT:
8405 case OCLASS_OPERATOR:
8406 case OCLASS_OPCLASS:
8407 case OCLASS_OPFAMILY:
8408 case OCLASS_AMOP:
8409 case OCLASS_AMPROC:
8410 case OCLASS_SCHEMA:
8411 case OCLASS_TSPARSER:
8412 case OCLASS_TSDICT:
8413 case OCLASS_TSTEMPLATE:
8414 case OCLASS_TSCONFIG:
8415 case OCLASS_ROLE:
8416 case OCLASS_DATABASE:
8417 case OCLASS_TBLSPACE:
8418 case OCLASS_FDW:
8419 case OCLASS_FOREIGN_SERVER:
8420 case OCLASS_USER_MAPPING:
8421 case OCLASS_DEFACL:
8422 case OCLASS_EXTENSION:
8423
8424 /*
8425 * We don't expect any of these sorts of objects to depend on
8426 * a column.
8427 */
8428 elog(ERROR, "unexpected object depending on column: %s",
8429 getObjectDescription(&foundObject));
8430 break;
8431
8432 default:
8433 elog(ERROR, "unrecognized object class: %u",
8434 foundObject.classId);
8435 }
8436 }
8437
8438 systable_endscan(scan);
8439
8440 /*
8441 * Now scan for dependencies of this column on other things. The only
8442 * thing we should find is the dependency on the column datatype, which we
8443 * want to remove, and possibly a collation dependency.
8444 */
8445 ScanKeyInit(&key[0],
8446 Anum_pg_depend_classid,
8447 BTEqualStrategyNumber, F_OIDEQ,
8448 ObjectIdGetDatum(RelationRelationId));
8449 ScanKeyInit(&key[1],
8450 Anum_pg_depend_objid,
8451 BTEqualStrategyNumber, F_OIDEQ,
8452 ObjectIdGetDatum(RelationGetRelid(rel)));
8453 ScanKeyInit(&key[2],
8454 Anum_pg_depend_objsubid,
8455 BTEqualStrategyNumber, F_INT4EQ,
8456 Int32GetDatum((int32) attnum));
8457
8458 scan = systable_beginscan(depRel, DependDependerIndexId, true,
8459 NULL, 3, key);
8460
8461 while (HeapTupleIsValid(depTup = systable_getnext(scan)))
8462 {
8463 Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
8464
8465 if (foundDep->deptype != DEPENDENCY_NORMAL)
8466 elog(ERROR, "found unexpected dependency type '%c'",
8467 foundDep->deptype);
8468 if (!(foundDep->refclassid == TypeRelationId &&
8469 foundDep->refobjid == attTup->atttypid) &&
8470 !(foundDep->refclassid == CollationRelationId &&
8471 foundDep->refobjid == attTup->attcollation))
8472 elog(ERROR, "found unexpected dependency for column");
8473
8474 simple_heap_delete(depRel, &depTup->t_self);
8475 }
8476
8477 systable_endscan(scan);
8478
8479 heap_close(depRel, RowExclusiveLock);
8480
8481 /*
8482 * Here we go --- change the recorded column type and collation. (Note
8483 * heapTup is a copy of the syscache entry, so okay to scribble on.)
8484 */
8485 attTup->atttypid = targettype;
8486 attTup->atttypmod = targettypmod;
8487 attTup->attcollation = targetcollid;
8488 attTup->attndims = list_length(typeName->arrayBounds);
8489 attTup->attlen = tform->typlen;
8490 attTup->attbyval = tform->typbyval;
8491 attTup->attalign = tform->typalign;
8492 attTup->attstorage = tform->typstorage;
8493
8494 ReleaseSysCache(typeTuple);
8495
8496 simple_heap_update(attrelation, &heapTup->t_self, heapTup);
8497
8498 /* keep system catalog indexes current */
8499 CatalogUpdateIndexes(attrelation, heapTup);
8500
8501 heap_close(attrelation, RowExclusiveLock);
8502
8503 /* Install dependencies on new datatype and collation */
8504 add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
8505 add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
8506
8507 /*
8508 * Drop any pg_statistic entry for the column, since it's now wrong type
8509 */
8510 RemoveStatistics(RelationGetRelid(rel), attnum);
8511
8512 InvokeObjectPostAlterHook(RelationRelationId,
8513 RelationGetRelid(rel), attnum);
8514
8515 /*
8516 * Update the default, if present, by brute force --- remove and re-add
8517 * the default. Probably unsafe to take shortcuts, since the new version
8518 * may well have additional dependencies. (It's okay to do this now,
8519 * rather than after other ALTER TYPE commands, since the default won't
8520 * depend on other column types.)
8521 */
8522 if (defaultexpr)
8523 {
8524 /* Must make new row visible since it will be updated again */
8525 CommandCounterIncrement();
8526
8527 /*
8528 * We use RESTRICT here for safety, but at present we do not expect
8529 * anything to depend on the default.
8530 */
8531 RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true,
8532 true);
8533
8534 StoreAttrDefault(rel, attnum, defaultexpr, true);
8535 }
8536
8537 ObjectAddressSubSet(address, RelationRelationId,
8538 RelationGetRelid(rel), attnum);
8539
8540 /* Cleanup */
8541 heap_freetuple(heapTup);
8542
8543 return address;
8544 }
8545
8546 /*
8547 * Subroutine for ATExecAlterColumnType: remember that a replica identity
8548 * needs to be reset.
8549 */
8550 static void
RememberReplicaIdentityForRebuilding(Oid indoid,AlteredTableInfo * tab)8551 RememberReplicaIdentityForRebuilding(Oid indoid, AlteredTableInfo *tab)
8552 {
8553 if (!get_index_isreplident(indoid))
8554 return;
8555
8556 if (tab->replicaIdentityIndex)
8557 elog(ERROR, "relation %u has multiple indexes marked as replica identity", tab->relid);
8558
8559 tab->replicaIdentityIndex = get_rel_name(indoid);
8560 }
8561
8562 /*
8563 * Subroutine for ATExecAlterColumnType: remember any clustered index.
8564 */
8565 static void
RememberClusterOnForRebuilding(Oid indoid,AlteredTableInfo * tab)8566 RememberClusterOnForRebuilding(Oid indoid, AlteredTableInfo *tab)
8567 {
8568 if (!get_index_isclustered(indoid))
8569 return;
8570
8571 if (tab->clusterOnIndex)
8572 elog(ERROR, "relation %u has multiple clustered indexes", tab->relid);
8573
8574 tab->clusterOnIndex = get_rel_name(indoid);
8575 }
8576
8577 /*
8578 * Subroutine for ATExecAlterColumnType: remember that a constraint needs
8579 * to be rebuilt (which we might already know).
8580 */
8581 static void
RememberConstraintForRebuilding(Oid conoid,AlteredTableInfo * tab,DependencyType deptype)8582 RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab,
8583 DependencyType deptype)
8584 {
8585 /*
8586 * This de-duplication check is critical for two independent reasons: we
8587 * mustn't try to recreate the same constraint twice, and if a constraint
8588 * depends on more than one column whose type is to be altered, we must
8589 * capture its definition string before applying any of the column type
8590 * changes. ruleutils.c will get confused if we ask again later.
8591 */
8592 if (!list_member_oid(tab->changedConstraintOids, conoid))
8593 {
8594 /* OK, capture the constraint's existing definition string */
8595 char *defstring = pg_get_constraintdef_command(conoid);
8596 Oid indoid;
8597
8598 /*
8599 * Put NORMAL dependencies at the front of the list and AUTO
8600 * dependencies at the back. This makes sure that foreign-key
8601 * constraints depending on this column will be dropped before unique
8602 * or primary-key constraints of the column; which we must have
8603 * because the FK constraints depend on the indexes belonging to the
8604 * unique constraints.
8605 */
8606 if (deptype == DEPENDENCY_NORMAL)
8607 {
8608 tab->changedConstraintOids = lcons_oid(conoid,
8609 tab->changedConstraintOids);
8610 tab->changedConstraintDefs = lcons(defstring,
8611 tab->changedConstraintDefs);
8612 }
8613 else
8614 {
8615 tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids,
8616 conoid);
8617 tab->changedConstraintDefs = lappend(tab->changedConstraintDefs,
8618 defstring);
8619 }
8620
8621 /*
8622 * For the index of a constraint, if any, remember if it is used for
8623 * the table's replica identity or if it is a clustered index, so that
8624 * ATPostAlterTypeCleanup() can queue up commands necessary to restore
8625 * those properties.
8626 */
8627 indoid = get_constraint_index(conoid);
8628 if (OidIsValid(indoid))
8629 {
8630 RememberReplicaIdentityForRebuilding(indoid, tab);
8631 RememberClusterOnForRebuilding(indoid, tab);
8632 }
8633 }
8634 }
8635
8636 /*
8637 * Subroutine for ATExecAlterColumnType: remember that an index needs
8638 * to be rebuilt (which we might already know).
8639 */
8640 static void
RememberIndexForRebuilding(Oid indoid,AlteredTableInfo * tab)8641 RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab)
8642 {
8643 /*
8644 * This de-duplication check is critical for two independent reasons: we
8645 * mustn't try to recreate the same index twice, and if an index depends
8646 * on more than one column whose type is to be altered, we must capture
8647 * its definition string before applying any of the column type changes.
8648 * ruleutils.c will get confused if we ask again later.
8649 */
8650 if (!list_member_oid(tab->changedIndexOids, indoid))
8651 {
8652 /*
8653 * Before adding it as an index-to-rebuild, we'd better see if it
8654 * belongs to a constraint, and if so rebuild the constraint instead.
8655 * Typically this check fails, because constraint indexes normally
8656 * have only dependencies on their constraint. But it's possible for
8657 * such an index to also have direct dependencies on table columns,
8658 * for example with a partial exclusion constraint.
8659 */
8660 Oid conoid = get_index_constraint(indoid);
8661
8662 if (OidIsValid(conoid))
8663 {
8664 /* index dependencies on columns should generally be AUTO */
8665 RememberConstraintForRebuilding(conoid, tab, DEPENDENCY_AUTO);
8666 }
8667 else
8668 {
8669 /* OK, capture the index's existing definition string */
8670 char *defstring = pg_get_indexdef_string(indoid);
8671
8672 tab->changedIndexOids = lappend_oid(tab->changedIndexOids,
8673 indoid);
8674 tab->changedIndexDefs = lappend(tab->changedIndexDefs,
8675 defstring);
8676
8677 /*
8678 * Remember if this index is used for the table's replica identity
8679 * or if it is a clustered index, so that ATPostAlterTypeCleanup()
8680 * can queue up commands necessary to restore those properties.
8681 */
8682 RememberReplicaIdentityForRebuilding(indoid, tab);
8683 RememberClusterOnForRebuilding(indoid, tab);
8684 }
8685 }
8686 }
8687
8688 /*
8689 * Returns the address of the modified column
8690 */
8691 static ObjectAddress
ATExecAlterColumnGenericOptions(Relation rel,const char * colName,List * options,LOCKMODE lockmode)8692 ATExecAlterColumnGenericOptions(Relation rel,
8693 const char *colName,
8694 List *options,
8695 LOCKMODE lockmode)
8696 {
8697 Relation ftrel;
8698 Relation attrel;
8699 ForeignServer *server;
8700 ForeignDataWrapper *fdw;
8701 HeapTuple tuple;
8702 HeapTuple newtuple;
8703 bool isnull;
8704 Datum repl_val[Natts_pg_attribute];
8705 bool repl_null[Natts_pg_attribute];
8706 bool repl_repl[Natts_pg_attribute];
8707 Datum datum;
8708 Form_pg_foreign_table fttableform;
8709 Form_pg_attribute atttableform;
8710 AttrNumber attnum;
8711 ObjectAddress address;
8712
8713 if (options == NIL)
8714 return InvalidObjectAddress;
8715
8716 /* First, determine FDW validator associated to the foreign table. */
8717 ftrel = heap_open(ForeignTableRelationId, AccessShareLock);
8718 tuple = SearchSysCache1(FOREIGNTABLEREL, rel->rd_id);
8719 if (!HeapTupleIsValid(tuple))
8720 ereport(ERROR,
8721 (errcode(ERRCODE_UNDEFINED_OBJECT),
8722 errmsg("foreign table \"%s\" does not exist",
8723 RelationGetRelationName(rel))));
8724 fttableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
8725 server = GetForeignServer(fttableform->ftserver);
8726 fdw = GetForeignDataWrapper(server->fdwid);
8727
8728 heap_close(ftrel, AccessShareLock);
8729 ReleaseSysCache(tuple);
8730
8731 attrel = heap_open(AttributeRelationId, RowExclusiveLock);
8732 tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
8733 if (!HeapTupleIsValid(tuple))
8734 ereport(ERROR,
8735 (errcode(ERRCODE_UNDEFINED_COLUMN),
8736 errmsg("column \"%s\" of relation \"%s\" does not exist",
8737 colName, RelationGetRelationName(rel))));
8738
8739 /* Prevent them from altering a system attribute */
8740 atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
8741 attnum = atttableform->attnum;
8742 if (attnum <= 0)
8743 ereport(ERROR,
8744 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
8745 errmsg("cannot alter system column \"%s\"", colName)));
8746
8747
8748 /* Initialize buffers for new tuple values */
8749 memset(repl_val, 0, sizeof(repl_val));
8750 memset(repl_null, false, sizeof(repl_null));
8751 memset(repl_repl, false, sizeof(repl_repl));
8752
8753 /* Extract the current options */
8754 datum = SysCacheGetAttr(ATTNAME,
8755 tuple,
8756 Anum_pg_attribute_attfdwoptions,
8757 &isnull);
8758 if (isnull)
8759 datum = PointerGetDatum(NULL);
8760
8761 /* Transform the options */
8762 datum = transformGenericOptions(AttributeRelationId,
8763 datum,
8764 options,
8765 fdw->fdwvalidator);
8766
8767 if (PointerIsValid(DatumGetPointer(datum)))
8768 repl_val[Anum_pg_attribute_attfdwoptions - 1] = datum;
8769 else
8770 repl_null[Anum_pg_attribute_attfdwoptions - 1] = true;
8771
8772 repl_repl[Anum_pg_attribute_attfdwoptions - 1] = true;
8773
8774 /* Everything looks good - update the tuple */
8775
8776 newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrel),
8777 repl_val, repl_null, repl_repl);
8778
8779 simple_heap_update(attrel, &newtuple->t_self, newtuple);
8780 CatalogUpdateIndexes(attrel, newtuple);
8781
8782 InvokeObjectPostAlterHook(RelationRelationId,
8783 RelationGetRelid(rel),
8784 atttableform->attnum);
8785 ObjectAddressSubSet(address, RelationRelationId,
8786 RelationGetRelid(rel), attnum);
8787
8788 ReleaseSysCache(tuple);
8789
8790 heap_close(attrel, RowExclusiveLock);
8791
8792 heap_freetuple(newtuple);
8793
8794 return address;
8795 }
8796
8797 /*
8798 * Cleanup after we've finished all the ALTER TYPE operations for a
8799 * particular relation. We have to drop and recreate all the indexes
8800 * and constraints that depend on the altered columns.
8801 */
8802 static void
ATPostAlterTypeCleanup(List ** wqueue,AlteredTableInfo * tab,LOCKMODE lockmode)8803 ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode)
8804 {
8805 ObjectAddress obj;
8806 ListCell *def_item;
8807 ListCell *oid_item;
8808
8809 /*
8810 * Re-parse the index and constraint definitions, and attach them to the
8811 * appropriate work queue entries. We do this before dropping because in
8812 * the case of a FOREIGN KEY constraint, we might not yet have exclusive
8813 * lock on the table the constraint is attached to, and we need to get
8814 * that before reparsing/dropping.
8815 *
8816 * We can't rely on the output of deparsing to tell us which relation to
8817 * operate on, because concurrent activity might have made the name
8818 * resolve differently. Instead, we've got to use the OID of the
8819 * constraint or index we're processing to figure out which relation to
8820 * operate on.
8821 */
8822 forboth(oid_item, tab->changedConstraintOids,
8823 def_item, tab->changedConstraintDefs)
8824 {
8825 Oid oldId = lfirst_oid(oid_item);
8826 HeapTuple tup;
8827 Form_pg_constraint con;
8828 Oid relid;
8829 Oid confrelid;
8830 char contype;
8831 bool conislocal;
8832
8833 tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
8834 if (!HeapTupleIsValid(tup)) /* should not happen */
8835 elog(ERROR, "cache lookup failed for constraint %u", oldId);
8836 con = (Form_pg_constraint) GETSTRUCT(tup);
8837 relid = con->conrelid;
8838 confrelid = con->confrelid;
8839 contype = con->contype;
8840 conislocal = con->conislocal;
8841 ReleaseSysCache(tup);
8842
8843 /*
8844 * If the constraint is inherited (only), we don't want to inject a
8845 * new definition here; it'll get recreated when ATAddCheckConstraint
8846 * recurses from adding the parent table's constraint. But we had to
8847 * carry the info this far so that we can drop the constraint below.
8848 */
8849 if (!conislocal)
8850 continue;
8851
8852 /*
8853 * When rebuilding an FK constraint that references the table we're
8854 * modifying, we might not yet have any lock on the FK's table, so get
8855 * one now. We'll need AccessExclusiveLock for the DROP CONSTRAINT
8856 * step, so there's no value in asking for anything weaker.
8857 */
8858 if (relid != tab->relid && contype == CONSTRAINT_FOREIGN)
8859 LockRelationOid(relid, AccessExclusiveLock);
8860
8861 ATPostAlterTypeParse(oldId, relid, confrelid,
8862 (char *) lfirst(def_item),
8863 wqueue, lockmode, tab->rewrite);
8864 }
8865 forboth(oid_item, tab->changedIndexOids,
8866 def_item, tab->changedIndexDefs)
8867 {
8868 Oid oldId = lfirst_oid(oid_item);
8869 Oid relid;
8870
8871 relid = IndexGetRelation(oldId, false);
8872 ATPostAlterTypeParse(oldId, relid, InvalidOid,
8873 (char *) lfirst(def_item),
8874 wqueue, lockmode, tab->rewrite);
8875 }
8876
8877 /*
8878 * Queue up command to restore replica identity index marking
8879 */
8880 if (tab->replicaIdentityIndex)
8881 {
8882 AlterTableCmd *cmd = makeNode(AlterTableCmd);
8883 ReplicaIdentityStmt *subcmd = makeNode(ReplicaIdentityStmt);
8884
8885 subcmd->identity_type = REPLICA_IDENTITY_INDEX;
8886 subcmd->name = tab->replicaIdentityIndex;
8887 cmd->subtype = AT_ReplicaIdentity;
8888 cmd->def = (Node *) subcmd;
8889
8890 /* do it after indexes and constraints */
8891 tab->subcmds[AT_PASS_OLD_CONSTR] =
8892 lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
8893 }
8894
8895 /*
8896 * Queue up command to restore marking of index used for cluster.
8897 */
8898 if (tab->clusterOnIndex)
8899 {
8900 AlterTableCmd *cmd = makeNode(AlterTableCmd);
8901
8902 cmd->subtype = AT_ClusterOn;
8903 cmd->name = tab->clusterOnIndex;
8904
8905 /* do it after indexes and constraints */
8906 tab->subcmds[AT_PASS_OLD_CONSTR] =
8907 lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
8908 }
8909
8910 /*
8911 * Now we can drop the existing constraints and indexes --- constraints
8912 * first, since some of them might depend on the indexes. In fact, we
8913 * have to delete FOREIGN KEY constraints before UNIQUE constraints, but
8914 * we already ordered the constraint list to ensure that would happen. It
8915 * should be okay to use DROP_RESTRICT here, since nothing else should be
8916 * depending on these objects.
8917 */
8918 foreach(oid_item, tab->changedConstraintOids)
8919 {
8920 obj.classId = ConstraintRelationId;
8921 obj.objectId = lfirst_oid(oid_item);
8922 obj.objectSubId = 0;
8923 performDeletion(&obj, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
8924 }
8925
8926 foreach(oid_item, tab->changedIndexOids)
8927 {
8928 obj.classId = RelationRelationId;
8929 obj.objectId = lfirst_oid(oid_item);
8930 obj.objectSubId = 0;
8931 performDeletion(&obj, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
8932 }
8933
8934 /*
8935 * The objects will get recreated during subsequent passes over the work
8936 * queue.
8937 */
8938 }
8939
8940 static void
ATPostAlterTypeParse(Oid oldId,Oid oldRelId,Oid refRelId,char * cmd,List ** wqueue,LOCKMODE lockmode,bool rewrite)8941 ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd,
8942 List **wqueue, LOCKMODE lockmode, bool rewrite)
8943 {
8944 List *raw_parsetree_list;
8945 List *querytree_list;
8946 ListCell *list_item;
8947 Relation rel;
8948
8949 /*
8950 * We expect that we will get only ALTER TABLE and CREATE INDEX
8951 * statements. Hence, there is no need to pass them through
8952 * parse_analyze() or the rewriter, but instead we need to pass them
8953 * through parse_utilcmd.c to make them ready for execution.
8954 */
8955 raw_parsetree_list = raw_parser(cmd);
8956 querytree_list = NIL;
8957 foreach(list_item, raw_parsetree_list)
8958 {
8959 Node *stmt = (Node *) lfirst(list_item);
8960
8961 if (IsA(stmt, IndexStmt))
8962 querytree_list = lappend(querytree_list,
8963 transformIndexStmt(oldRelId,
8964 (IndexStmt *) stmt,
8965 cmd));
8966 else if (IsA(stmt, AlterTableStmt))
8967 querytree_list = list_concat(querytree_list,
8968 transformAlterTableStmt(oldRelId,
8969 (AlterTableStmt *) stmt,
8970 cmd));
8971 else
8972 querytree_list = lappend(querytree_list, stmt);
8973 }
8974
8975 /* Caller should already have acquired whatever lock we need. */
8976 rel = relation_open(oldRelId, NoLock);
8977
8978 /*
8979 * Attach each generated command to the proper place in the work queue.
8980 * Note this could result in creation of entirely new work-queue entries.
8981 *
8982 * Also note that we have to tweak the command subtypes, because it turns
8983 * out that re-creation of indexes and constraints has to act a bit
8984 * differently from initial creation.
8985 */
8986 foreach(list_item, querytree_list)
8987 {
8988 Node *stm = (Node *) lfirst(list_item);
8989 AlteredTableInfo *tab;
8990
8991 tab = ATGetQueueEntry(wqueue, rel);
8992
8993 if (IsA(stm, IndexStmt))
8994 {
8995 IndexStmt *stmt = (IndexStmt *) stm;
8996 AlterTableCmd *newcmd;
8997
8998 if (!rewrite)
8999 TryReuseIndex(oldId, stmt);
9000 /* keep the index's comment */
9001 stmt->idxcomment = GetComment(oldId, RelationRelationId, 0);
9002
9003 newcmd = makeNode(AlterTableCmd);
9004 newcmd->subtype = AT_ReAddIndex;
9005 newcmd->def = (Node *) stmt;
9006 tab->subcmds[AT_PASS_OLD_INDEX] =
9007 lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd);
9008 }
9009 else if (IsA(stm, AlterTableStmt))
9010 {
9011 AlterTableStmt *stmt = (AlterTableStmt *) stm;
9012 ListCell *lcmd;
9013
9014 foreach(lcmd, stmt->cmds)
9015 {
9016 AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
9017
9018 if (cmd->subtype == AT_AddIndex)
9019 {
9020 IndexStmt *indstmt;
9021 Oid indoid;
9022
9023 Assert(IsA(cmd->def, IndexStmt));
9024
9025 indstmt = (IndexStmt *) cmd->def;
9026 indoid = get_constraint_index(oldId);
9027
9028 if (!rewrite)
9029 TryReuseIndex(indoid, indstmt);
9030 /* keep any comment on the index */
9031 indstmt->idxcomment = GetComment(indoid,
9032 RelationRelationId, 0);
9033
9034 cmd->subtype = AT_ReAddIndex;
9035 tab->subcmds[AT_PASS_OLD_INDEX] =
9036 lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd);
9037
9038 /* recreate any comment on the constraint */
9039 RebuildConstraintComment(tab,
9040 AT_PASS_OLD_INDEX,
9041 oldId,
9042 rel, indstmt->idxname);
9043 }
9044 else if (cmd->subtype == AT_AddConstraint)
9045 {
9046 Constraint *con;
9047
9048 Assert(IsA(cmd->def, Constraint));
9049
9050 con = (Constraint *) cmd->def;
9051 con->old_pktable_oid = refRelId;
9052 /* rewriting neither side of a FK */
9053 if (con->contype == CONSTR_FOREIGN &&
9054 !rewrite && tab->rewrite == 0)
9055 TryReuseForeignKey(oldId, con);
9056 cmd->subtype = AT_ReAddConstraint;
9057 tab->subcmds[AT_PASS_OLD_CONSTR] =
9058 lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
9059
9060 /* recreate any comment on the constraint */
9061 RebuildConstraintComment(tab,
9062 AT_PASS_OLD_CONSTR,
9063 oldId,
9064 rel, con->conname);
9065 }
9066 else
9067 elog(ERROR, "unexpected statement subtype: %d",
9068 (int) cmd->subtype);
9069 }
9070 }
9071 else
9072 elog(ERROR, "unexpected statement type: %d",
9073 (int) nodeTag(stm));
9074 }
9075
9076 relation_close(rel, NoLock);
9077 }
9078
9079 /*
9080 * Subroutine for ATPostAlterTypeParse() to recreate a comment entry for
9081 * a constraint that is being re-added.
9082 */
9083 static void
RebuildConstraintComment(AlteredTableInfo * tab,int pass,Oid objid,Relation rel,char * conname)9084 RebuildConstraintComment(AlteredTableInfo *tab, int pass, Oid objid,
9085 Relation rel, char *conname)
9086 {
9087 CommentStmt *cmd;
9088 char *comment_str;
9089 AlterTableCmd *newcmd;
9090
9091 /* Look for comment for object wanted, and leave if none */
9092 comment_str = GetComment(objid, ConstraintRelationId, 0);
9093 if (comment_str == NULL)
9094 return;
9095
9096 /* Build node CommentStmt */
9097 cmd = makeNode(CommentStmt);
9098 cmd->objtype = OBJECT_TABCONSTRAINT;
9099 cmd->objname = list_make3(
9100 makeString(get_namespace_name(RelationGetNamespace(rel))),
9101 makeString(pstrdup(RelationGetRelationName(rel))),
9102 makeString(pstrdup(conname)));
9103 cmd->objargs = NIL;
9104 cmd->comment = comment_str;
9105
9106 /* Append it to list of commands */
9107 newcmd = makeNode(AlterTableCmd);
9108 newcmd->subtype = AT_ReAddComment;
9109 newcmd->def = (Node *) cmd;
9110 tab->subcmds[pass] = lappend(tab->subcmds[pass], newcmd);
9111 }
9112
9113 /*
9114 * Subroutine for ATPostAlterTypeParse(). Calls out to CheckIndexCompatible()
9115 * for the real analysis, then mutates the IndexStmt based on that verdict.
9116 */
9117 static void
TryReuseIndex(Oid oldId,IndexStmt * stmt)9118 TryReuseIndex(Oid oldId, IndexStmt *stmt)
9119 {
9120 if (CheckIndexCompatible(oldId,
9121 stmt->accessMethod,
9122 stmt->indexParams,
9123 stmt->excludeOpNames))
9124 {
9125 Relation irel = index_open(oldId, NoLock);
9126
9127 stmt->oldNode = irel->rd_node.relNode;
9128 index_close(irel, NoLock);
9129 }
9130 }
9131
9132 /*
9133 * Subroutine for ATPostAlterTypeParse().
9134 *
9135 * Stash the old P-F equality operator into the Constraint node, for possible
9136 * use by ATAddForeignKeyConstraint() in determining whether revalidation of
9137 * this constraint can be skipped.
9138 */
9139 static void
TryReuseForeignKey(Oid oldId,Constraint * con)9140 TryReuseForeignKey(Oid oldId, Constraint *con)
9141 {
9142 HeapTuple tup;
9143 Datum adatum;
9144 bool isNull;
9145 ArrayType *arr;
9146 Oid *rawarr;
9147 int numkeys;
9148 int i;
9149
9150 Assert(con->contype == CONSTR_FOREIGN);
9151 Assert(con->old_conpfeqop == NIL); /* already prepared this node */
9152
9153 tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
9154 if (!HeapTupleIsValid(tup)) /* should not happen */
9155 elog(ERROR, "cache lookup failed for constraint %u", oldId);
9156
9157 adatum = SysCacheGetAttr(CONSTROID, tup,
9158 Anum_pg_constraint_conpfeqop, &isNull);
9159 if (isNull)
9160 elog(ERROR, "null conpfeqop for constraint %u", oldId);
9161 arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
9162 numkeys = ARR_DIMS(arr)[0];
9163 /* test follows the one in ri_FetchConstraintInfo() */
9164 if (ARR_NDIM(arr) != 1 ||
9165 ARR_HASNULL(arr) ||
9166 ARR_ELEMTYPE(arr) != OIDOID)
9167 elog(ERROR, "conpfeqop is not a 1-D Oid array");
9168 rawarr = (Oid *) ARR_DATA_PTR(arr);
9169
9170 /* stash a List of the operator Oids in our Constraint node */
9171 for (i = 0; i < numkeys; i++)
9172 con->old_conpfeqop = lappend_oid(con->old_conpfeqop, rawarr[i]);
9173
9174 ReleaseSysCache(tup);
9175 }
9176
9177 /*
9178 * ALTER TABLE OWNER
9179 *
9180 * recursing is true if we are recursing from a table to its indexes,
9181 * sequences, or toast table. We don't allow the ownership of those things to
9182 * be changed separately from the parent table. Also, we can skip permission
9183 * checks (this is necessary not just an optimization, else we'd fail to
9184 * handle toast tables properly).
9185 *
9186 * recursing is also true if ALTER TYPE OWNER is calling us to fix up a
9187 * free-standing composite type.
9188 */
9189 void
ATExecChangeOwner(Oid relationOid,Oid newOwnerId,bool recursing,LOCKMODE lockmode)9190 ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing, LOCKMODE lockmode)
9191 {
9192 Relation target_rel;
9193 Relation class_rel;
9194 HeapTuple tuple;
9195 Form_pg_class tuple_class;
9196
9197 /*
9198 * Get exclusive lock till end of transaction on the target table. Use
9199 * relation_open so that we can work on indexes and sequences.
9200 */
9201 target_rel = relation_open(relationOid, lockmode);
9202
9203 /* Get its pg_class tuple, too */
9204 class_rel = heap_open(RelationRelationId, RowExclusiveLock);
9205
9206 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relationOid));
9207 if (!HeapTupleIsValid(tuple))
9208 elog(ERROR, "cache lookup failed for relation %u", relationOid);
9209 tuple_class = (Form_pg_class) GETSTRUCT(tuple);
9210
9211 /* Can we change the ownership of this tuple? */
9212 switch (tuple_class->relkind)
9213 {
9214 case RELKIND_RELATION:
9215 case RELKIND_VIEW:
9216 case RELKIND_MATVIEW:
9217 case RELKIND_FOREIGN_TABLE:
9218 /* ok to change owner */
9219 break;
9220 case RELKIND_INDEX:
9221 if (!recursing)
9222 {
9223 /*
9224 * Because ALTER INDEX OWNER used to be allowed, and in fact
9225 * is generated by old versions of pg_dump, we give a warning
9226 * and do nothing rather than erroring out. Also, to avoid
9227 * unnecessary chatter while restoring those old dumps, say
9228 * nothing at all if the command would be a no-op anyway.
9229 */
9230 if (tuple_class->relowner != newOwnerId)
9231 ereport(WARNING,
9232 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
9233 errmsg("cannot change owner of index \"%s\"",
9234 NameStr(tuple_class->relname)),
9235 errhint("Change the ownership of the index's table, instead.")));
9236 /* quick hack to exit via the no-op path */
9237 newOwnerId = tuple_class->relowner;
9238 }
9239 break;
9240 case RELKIND_SEQUENCE:
9241 if (!recursing &&
9242 tuple_class->relowner != newOwnerId)
9243 {
9244 /* if it's an owned sequence, disallow changing it by itself */
9245 Oid tableId;
9246 int32 colId;
9247
9248 if (sequenceIsOwned(relationOid, &tableId, &colId))
9249 ereport(ERROR,
9250 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
9251 errmsg("cannot change owner of sequence \"%s\"",
9252 NameStr(tuple_class->relname)),
9253 errdetail("Sequence \"%s\" is linked to table \"%s\".",
9254 NameStr(tuple_class->relname),
9255 get_rel_name(tableId))));
9256 }
9257 break;
9258 case RELKIND_COMPOSITE_TYPE:
9259 if (recursing)
9260 break;
9261 ereport(ERROR,
9262 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
9263 errmsg("\"%s\" is a composite type",
9264 NameStr(tuple_class->relname)),
9265 errhint("Use ALTER TYPE instead.")));
9266 break;
9267 case RELKIND_TOASTVALUE:
9268 if (recursing)
9269 break;
9270 /* FALL THRU */
9271 default:
9272 ereport(ERROR,
9273 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
9274 errmsg("\"%s\" is not a table, view, sequence, or foreign table",
9275 NameStr(tuple_class->relname))));
9276 }
9277
9278 /*
9279 * If the new owner is the same as the existing owner, consider the
9280 * command to have succeeded. This is for dump restoration purposes.
9281 */
9282 if (tuple_class->relowner != newOwnerId)
9283 {
9284 Datum repl_val[Natts_pg_class];
9285 bool repl_null[Natts_pg_class];
9286 bool repl_repl[Natts_pg_class];
9287 Acl *newAcl;
9288 Datum aclDatum;
9289 bool isNull;
9290 HeapTuple newtuple;
9291
9292 /* skip permission checks when recursing to index or toast table */
9293 if (!recursing)
9294 {
9295 /* Superusers can always do it */
9296 if (!superuser())
9297 {
9298 Oid namespaceOid = tuple_class->relnamespace;
9299 AclResult aclresult;
9300
9301 /* Otherwise, must be owner of the existing object */
9302 if (!pg_class_ownercheck(relationOid, GetUserId()))
9303 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
9304 RelationGetRelationName(target_rel));
9305
9306 /* Must be able to become new owner */
9307 check_is_member_of_role(GetUserId(), newOwnerId);
9308
9309 /* New owner must have CREATE privilege on namespace */
9310 aclresult = pg_namespace_aclcheck(namespaceOid, newOwnerId,
9311 ACL_CREATE);
9312 if (aclresult != ACLCHECK_OK)
9313 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
9314 get_namespace_name(namespaceOid));
9315 }
9316 }
9317
9318 memset(repl_null, false, sizeof(repl_null));
9319 memset(repl_repl, false, sizeof(repl_repl));
9320
9321 repl_repl[Anum_pg_class_relowner - 1] = true;
9322 repl_val[Anum_pg_class_relowner - 1] = ObjectIdGetDatum(newOwnerId);
9323
9324 /*
9325 * Determine the modified ACL for the new owner. This is only
9326 * necessary when the ACL is non-null.
9327 */
9328 aclDatum = SysCacheGetAttr(RELOID, tuple,
9329 Anum_pg_class_relacl,
9330 &isNull);
9331 if (!isNull)
9332 {
9333 newAcl = aclnewowner(DatumGetAclP(aclDatum),
9334 tuple_class->relowner, newOwnerId);
9335 repl_repl[Anum_pg_class_relacl - 1] = true;
9336 repl_val[Anum_pg_class_relacl - 1] = PointerGetDatum(newAcl);
9337 }
9338
9339 newtuple = heap_modify_tuple(tuple, RelationGetDescr(class_rel), repl_val, repl_null, repl_repl);
9340
9341 simple_heap_update(class_rel, &newtuple->t_self, newtuple);
9342 CatalogUpdateIndexes(class_rel, newtuple);
9343
9344 heap_freetuple(newtuple);
9345
9346 /*
9347 * We must similarly update any per-column ACLs to reflect the new
9348 * owner; for neatness reasons that's split out as a subroutine.
9349 */
9350 change_owner_fix_column_acls(relationOid,
9351 tuple_class->relowner,
9352 newOwnerId);
9353
9354 /*
9355 * Update owner dependency reference, if any. A composite type has
9356 * none, because it's tracked for the pg_type entry instead of here;
9357 * indexes and TOAST tables don't have their own entries either.
9358 */
9359 if (tuple_class->relkind != RELKIND_COMPOSITE_TYPE &&
9360 tuple_class->relkind != RELKIND_INDEX &&
9361 tuple_class->relkind != RELKIND_TOASTVALUE)
9362 changeDependencyOnOwner(RelationRelationId, relationOid,
9363 newOwnerId);
9364
9365 /*
9366 * Also change the ownership of the table's row type, if it has one
9367 */
9368 if (tuple_class->relkind != RELKIND_INDEX)
9369 AlterTypeOwnerInternal(tuple_class->reltype, newOwnerId);
9370
9371 /*
9372 * If we are operating on a table or materialized view, also change
9373 * the ownership of any indexes and sequences that belong to the
9374 * relation, as well as its toast table (if it has one).
9375 */
9376 if (tuple_class->relkind == RELKIND_RELATION ||
9377 tuple_class->relkind == RELKIND_MATVIEW ||
9378 tuple_class->relkind == RELKIND_TOASTVALUE)
9379 {
9380 List *index_oid_list;
9381 ListCell *i;
9382
9383 /* Find all the indexes belonging to this relation */
9384 index_oid_list = RelationGetIndexList(target_rel);
9385
9386 /* For each index, recursively change its ownership */
9387 foreach(i, index_oid_list)
9388 ATExecChangeOwner(lfirst_oid(i), newOwnerId, true, lockmode);
9389
9390 list_free(index_oid_list);
9391 }
9392
9393 /* If it has a toast table, recurse to change its ownership */
9394 if (tuple_class->reltoastrelid != InvalidOid)
9395 ATExecChangeOwner(tuple_class->reltoastrelid, newOwnerId,
9396 true, lockmode);
9397
9398 /* If it has dependent sequences, recurse to change them too */
9399 change_owner_recurse_to_sequences(relationOid, newOwnerId, lockmode);
9400 }
9401
9402 InvokeObjectPostAlterHook(RelationRelationId, relationOid, 0);
9403
9404 ReleaseSysCache(tuple);
9405 heap_close(class_rel, RowExclusiveLock);
9406 relation_close(target_rel, NoLock);
9407 }
9408
9409 /*
9410 * change_owner_fix_column_acls
9411 *
9412 * Helper function for ATExecChangeOwner. Scan the columns of the table
9413 * and fix any non-null column ACLs to reflect the new owner.
9414 */
9415 static void
change_owner_fix_column_acls(Oid relationOid,Oid oldOwnerId,Oid newOwnerId)9416 change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId)
9417 {
9418 Relation attRelation;
9419 SysScanDesc scan;
9420 ScanKeyData key[1];
9421 HeapTuple attributeTuple;
9422
9423 attRelation = heap_open(AttributeRelationId, RowExclusiveLock);
9424 ScanKeyInit(&key[0],
9425 Anum_pg_attribute_attrelid,
9426 BTEqualStrategyNumber, F_OIDEQ,
9427 ObjectIdGetDatum(relationOid));
9428 scan = systable_beginscan(attRelation, AttributeRelidNumIndexId,
9429 true, NULL, 1, key);
9430 while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
9431 {
9432 Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
9433 Datum repl_val[Natts_pg_attribute];
9434 bool repl_null[Natts_pg_attribute];
9435 bool repl_repl[Natts_pg_attribute];
9436 Acl *newAcl;
9437 Datum aclDatum;
9438 bool isNull;
9439 HeapTuple newtuple;
9440
9441 /* Ignore dropped columns */
9442 if (att->attisdropped)
9443 continue;
9444
9445 aclDatum = heap_getattr(attributeTuple,
9446 Anum_pg_attribute_attacl,
9447 RelationGetDescr(attRelation),
9448 &isNull);
9449 /* Null ACLs do not require changes */
9450 if (isNull)
9451 continue;
9452
9453 memset(repl_null, false, sizeof(repl_null));
9454 memset(repl_repl, false, sizeof(repl_repl));
9455
9456 newAcl = aclnewowner(DatumGetAclP(aclDatum),
9457 oldOwnerId, newOwnerId);
9458 repl_repl[Anum_pg_attribute_attacl - 1] = true;
9459 repl_val[Anum_pg_attribute_attacl - 1] = PointerGetDatum(newAcl);
9460
9461 newtuple = heap_modify_tuple(attributeTuple,
9462 RelationGetDescr(attRelation),
9463 repl_val, repl_null, repl_repl);
9464
9465 simple_heap_update(attRelation, &newtuple->t_self, newtuple);
9466 CatalogUpdateIndexes(attRelation, newtuple);
9467
9468 heap_freetuple(newtuple);
9469 }
9470 systable_endscan(scan);
9471 heap_close(attRelation, RowExclusiveLock);
9472 }
9473
9474 /*
9475 * change_owner_recurse_to_sequences
9476 *
9477 * Helper function for ATExecChangeOwner. Examines pg_depend searching
9478 * for sequences that are dependent on serial columns, and changes their
9479 * ownership.
9480 */
9481 static void
change_owner_recurse_to_sequences(Oid relationOid,Oid newOwnerId,LOCKMODE lockmode)9482 change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode)
9483 {
9484 Relation depRel;
9485 SysScanDesc scan;
9486 ScanKeyData key[2];
9487 HeapTuple tup;
9488
9489 /*
9490 * SERIAL sequences are those having an auto dependency on one of the
9491 * table's columns (we don't care *which* column, exactly).
9492 */
9493 depRel = heap_open(DependRelationId, AccessShareLock);
9494
9495 ScanKeyInit(&key[0],
9496 Anum_pg_depend_refclassid,
9497 BTEqualStrategyNumber, F_OIDEQ,
9498 ObjectIdGetDatum(RelationRelationId));
9499 ScanKeyInit(&key[1],
9500 Anum_pg_depend_refobjid,
9501 BTEqualStrategyNumber, F_OIDEQ,
9502 ObjectIdGetDatum(relationOid));
9503 /* we leave refobjsubid unspecified */
9504
9505 scan = systable_beginscan(depRel, DependReferenceIndexId, true,
9506 NULL, 2, key);
9507
9508 while (HeapTupleIsValid(tup = systable_getnext(scan)))
9509 {
9510 Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
9511 Relation seqRel;
9512
9513 /* skip dependencies other than auto dependencies on columns */
9514 if (depForm->refobjsubid == 0 ||
9515 depForm->classid != RelationRelationId ||
9516 depForm->objsubid != 0 ||
9517 depForm->deptype != DEPENDENCY_AUTO)
9518 continue;
9519
9520 /* Use relation_open just in case it's an index */
9521 seqRel = relation_open(depForm->objid, lockmode);
9522
9523 /* skip non-sequence relations */
9524 if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
9525 {
9526 /* No need to keep the lock */
9527 relation_close(seqRel, lockmode);
9528 continue;
9529 }
9530
9531 /* We don't need to close the sequence while we alter it. */
9532 ATExecChangeOwner(depForm->objid, newOwnerId, true, lockmode);
9533
9534 /* Now we can close it. Keep the lock till end of transaction. */
9535 relation_close(seqRel, NoLock);
9536 }
9537
9538 systable_endscan(scan);
9539
9540 relation_close(depRel, AccessShareLock);
9541 }
9542
9543 /*
9544 * ALTER TABLE CLUSTER ON
9545 *
9546 * The only thing we have to do is to change the indisclustered bits.
9547 *
9548 * Return the address of the new clustering index.
9549 */
9550 static ObjectAddress
ATExecClusterOn(Relation rel,const char * indexName,LOCKMODE lockmode)9551 ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode)
9552 {
9553 Oid indexOid;
9554 ObjectAddress address;
9555
9556 indexOid = get_relname_relid(indexName, rel->rd_rel->relnamespace);
9557
9558 if (!OidIsValid(indexOid))
9559 ereport(ERROR,
9560 (errcode(ERRCODE_UNDEFINED_OBJECT),
9561 errmsg("index \"%s\" for table \"%s\" does not exist",
9562 indexName, RelationGetRelationName(rel))));
9563
9564 /* Check index is valid to cluster on */
9565 check_index_is_clusterable(rel, indexOid, false, lockmode);
9566
9567 /* And do the work */
9568 mark_index_clustered(rel, indexOid, false);
9569
9570 ObjectAddressSet(address,
9571 RelationRelationId, indexOid);
9572
9573 return address;
9574 }
9575
9576 /*
9577 * ALTER TABLE SET WITHOUT CLUSTER
9578 *
9579 * We have to find any indexes on the table that have indisclustered bit
9580 * set and turn it off.
9581 */
9582 static void
ATExecDropCluster(Relation rel,LOCKMODE lockmode)9583 ATExecDropCluster(Relation rel, LOCKMODE lockmode)
9584 {
9585 mark_index_clustered(rel, InvalidOid, false);
9586 }
9587
9588 /*
9589 * ALTER TABLE SET TABLESPACE
9590 */
9591 static void
ATPrepSetTableSpace(AlteredTableInfo * tab,Relation rel,char * tablespacename,LOCKMODE lockmode)9592 ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, char *tablespacename, LOCKMODE lockmode)
9593 {
9594 Oid tablespaceId;
9595
9596 /* Check that the tablespace exists */
9597 tablespaceId = get_tablespace_oid(tablespacename, false);
9598
9599 /* Check permissions except when moving to database's default */
9600 if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
9601 {
9602 AclResult aclresult;
9603
9604 aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(), ACL_CREATE);
9605 if (aclresult != ACLCHECK_OK)
9606 aclcheck_error(aclresult, ACL_KIND_TABLESPACE, tablespacename);
9607 }
9608
9609 /* Save info for Phase 3 to do the real work */
9610 if (OidIsValid(tab->newTableSpace))
9611 ereport(ERROR,
9612 (errcode(ERRCODE_SYNTAX_ERROR),
9613 errmsg("cannot have multiple SET TABLESPACE subcommands")));
9614
9615 tab->newTableSpace = tablespaceId;
9616 }
9617
9618 /*
9619 * Set, reset, or replace reloptions.
9620 */
9621 static void
ATExecSetRelOptions(Relation rel,List * defList,AlterTableType operation,LOCKMODE lockmode)9622 ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
9623 LOCKMODE lockmode)
9624 {
9625 Oid relid;
9626 Relation pgclass;
9627 HeapTuple tuple;
9628 HeapTuple newtuple;
9629 Datum datum;
9630 bool isnull;
9631 Datum newOptions;
9632 Datum repl_val[Natts_pg_class];
9633 bool repl_null[Natts_pg_class];
9634 bool repl_repl[Natts_pg_class];
9635 static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
9636
9637 if (defList == NIL && operation != AT_ReplaceRelOptions)
9638 return; /* nothing to do */
9639
9640 pgclass = heap_open(RelationRelationId, RowExclusiveLock);
9641
9642 /* Fetch heap tuple */
9643 relid = RelationGetRelid(rel);
9644 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
9645 if (!HeapTupleIsValid(tuple))
9646 elog(ERROR, "cache lookup failed for relation %u", relid);
9647
9648 if (operation == AT_ReplaceRelOptions)
9649 {
9650 /*
9651 * If we're supposed to replace the reloptions list, we just pretend
9652 * there were none before.
9653 */
9654 datum = (Datum) 0;
9655 isnull = true;
9656 }
9657 else
9658 {
9659 /* Get the old reloptions */
9660 datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
9661 &isnull);
9662 }
9663
9664 /* Generate new proposed reloptions (text array) */
9665 newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
9666 defList, NULL, validnsps, false,
9667 operation == AT_ResetRelOptions);
9668
9669 /* Validate */
9670 switch (rel->rd_rel->relkind)
9671 {
9672 case RELKIND_RELATION:
9673 case RELKIND_TOASTVALUE:
9674 case RELKIND_MATVIEW:
9675 (void) heap_reloptions(rel->rd_rel->relkind, newOptions, true);
9676 break;
9677 case RELKIND_VIEW:
9678 (void) view_reloptions(newOptions, true);
9679 break;
9680 case RELKIND_INDEX:
9681 (void) index_reloptions(rel->rd_amroutine->amoptions, newOptions, true);
9682 break;
9683 default:
9684 ereport(ERROR,
9685 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
9686 errmsg("\"%s\" is not a table, view, materialized view, index, or TOAST table",
9687 RelationGetRelationName(rel))));
9688 break;
9689 }
9690
9691 /* Special-case validation of view options */
9692 if (rel->rd_rel->relkind == RELKIND_VIEW)
9693 {
9694 Query *view_query = get_view_query(rel);
9695 List *view_options = untransformRelOptions(newOptions);
9696 ListCell *cell;
9697 bool check_option = false;
9698
9699 foreach(cell, view_options)
9700 {
9701 DefElem *defel = (DefElem *) lfirst(cell);
9702
9703 if (pg_strcasecmp(defel->defname, "check_option") == 0)
9704 check_option = true;
9705 }
9706
9707 /*
9708 * If the check option is specified, look to see if the view is
9709 * actually auto-updatable or not.
9710 */
9711 if (check_option)
9712 {
9713 const char *view_updatable_error =
9714 view_query_is_auto_updatable(view_query, true);
9715
9716 if (view_updatable_error)
9717 ereport(ERROR,
9718 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
9719 errmsg("WITH CHECK OPTION is supported only on automatically updatable views"),
9720 errhint("%s", _(view_updatable_error))));
9721 }
9722 }
9723
9724 /*
9725 * All we need do here is update the pg_class row; the new options will be
9726 * propagated into relcaches during post-commit cache inval.
9727 */
9728 memset(repl_val, 0, sizeof(repl_val));
9729 memset(repl_null, false, sizeof(repl_null));
9730 memset(repl_repl, false, sizeof(repl_repl));
9731
9732 if (newOptions != (Datum) 0)
9733 repl_val[Anum_pg_class_reloptions - 1] = newOptions;
9734 else
9735 repl_null[Anum_pg_class_reloptions - 1] = true;
9736
9737 repl_repl[Anum_pg_class_reloptions - 1] = true;
9738
9739 newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
9740 repl_val, repl_null, repl_repl);
9741
9742 simple_heap_update(pgclass, &newtuple->t_self, newtuple);
9743
9744 CatalogUpdateIndexes(pgclass, newtuple);
9745
9746 InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
9747
9748 heap_freetuple(newtuple);
9749
9750 ReleaseSysCache(tuple);
9751
9752 /* repeat the whole exercise for the toast table, if there's one */
9753 if (OidIsValid(rel->rd_rel->reltoastrelid))
9754 {
9755 Relation toastrel;
9756 Oid toastid = rel->rd_rel->reltoastrelid;
9757
9758 toastrel = heap_open(toastid, lockmode);
9759
9760 /* Fetch heap tuple */
9761 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid));
9762 if (!HeapTupleIsValid(tuple))
9763 elog(ERROR, "cache lookup failed for relation %u", toastid);
9764
9765 if (operation == AT_ReplaceRelOptions)
9766 {
9767 /*
9768 * If we're supposed to replace the reloptions list, we just
9769 * pretend there were none before.
9770 */
9771 datum = (Datum) 0;
9772 isnull = true;
9773 }
9774 else
9775 {
9776 /* Get the old reloptions */
9777 datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
9778 &isnull);
9779 }
9780
9781 newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
9782 defList, "toast", validnsps, false,
9783 operation == AT_ResetRelOptions);
9784
9785 (void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true);
9786
9787 memset(repl_val, 0, sizeof(repl_val));
9788 memset(repl_null, false, sizeof(repl_null));
9789 memset(repl_repl, false, sizeof(repl_repl));
9790
9791 if (newOptions != (Datum) 0)
9792 repl_val[Anum_pg_class_reloptions - 1] = newOptions;
9793 else
9794 repl_null[Anum_pg_class_reloptions - 1] = true;
9795
9796 repl_repl[Anum_pg_class_reloptions - 1] = true;
9797
9798 newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
9799 repl_val, repl_null, repl_repl);
9800
9801 simple_heap_update(pgclass, &newtuple->t_self, newtuple);
9802
9803 CatalogUpdateIndexes(pgclass, newtuple);
9804
9805 InvokeObjectPostAlterHookArg(RelationRelationId,
9806 RelationGetRelid(toastrel), 0,
9807 InvalidOid, true);
9808
9809 heap_freetuple(newtuple);
9810
9811 ReleaseSysCache(tuple);
9812
9813 heap_close(toastrel, NoLock);
9814 }
9815
9816 heap_close(pgclass, RowExclusiveLock);
9817 }
9818
9819 /*
9820 * Execute ALTER TABLE SET TABLESPACE for cases where there is no tuple
9821 * rewriting to be done, so we just want to copy the data as fast as possible.
9822 */
9823 static void
ATExecSetTableSpace(Oid tableOid,Oid newTableSpace,LOCKMODE lockmode)9824 ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
9825 {
9826 Relation rel;
9827 Oid oldTableSpace;
9828 Oid reltoastrelid;
9829 Oid newrelfilenode;
9830 RelFileNode newrnode;
9831 SMgrRelation dstrel;
9832 Relation pg_class;
9833 HeapTuple tuple;
9834 Form_pg_class rd_rel;
9835 ForkNumber forkNum;
9836 List *reltoastidxids = NIL;
9837 ListCell *lc;
9838
9839 /*
9840 * Need lock here in case we are recursing to toast table or index
9841 */
9842 rel = relation_open(tableOid, lockmode);
9843
9844 /*
9845 * No work if no change in tablespace.
9846 */
9847 oldTableSpace = rel->rd_rel->reltablespace;
9848 if (newTableSpace == oldTableSpace ||
9849 (newTableSpace == MyDatabaseTableSpace && oldTableSpace == 0))
9850 {
9851 InvokeObjectPostAlterHook(RelationRelationId,
9852 RelationGetRelid(rel), 0);
9853
9854 relation_close(rel, NoLock);
9855 return;
9856 }
9857
9858 /*
9859 * We cannot support moving mapped relations into different tablespaces.
9860 * (In particular this eliminates all shared catalogs.)
9861 */
9862 if (RelationIsMapped(rel))
9863 ereport(ERROR,
9864 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
9865 errmsg("cannot move system relation \"%s\"",
9866 RelationGetRelationName(rel))));
9867
9868 /* Can't move a non-shared relation into pg_global */
9869 if (newTableSpace == GLOBALTABLESPACE_OID)
9870 ereport(ERROR,
9871 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
9872 errmsg("only shared relations can be placed in pg_global tablespace")));
9873
9874 /*
9875 * Don't allow moving temp tables of other backends ... their local buffer
9876 * manager is not going to cope.
9877 */
9878 if (RELATION_IS_OTHER_TEMP(rel))
9879 ereport(ERROR,
9880 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
9881 errmsg("cannot move temporary tables of other sessions")));
9882
9883 reltoastrelid = rel->rd_rel->reltoastrelid;
9884 /* Fetch the list of indexes on toast relation if necessary */
9885 if (OidIsValid(reltoastrelid))
9886 {
9887 Relation toastRel = relation_open(reltoastrelid, lockmode);
9888
9889 reltoastidxids = RelationGetIndexList(toastRel);
9890 relation_close(toastRel, lockmode);
9891 }
9892
9893 /* Get a modifiable copy of the relation's pg_class row */
9894 pg_class = heap_open(RelationRelationId, RowExclusiveLock);
9895
9896 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(tableOid));
9897 if (!HeapTupleIsValid(tuple))
9898 elog(ERROR, "cache lookup failed for relation %u", tableOid);
9899 rd_rel = (Form_pg_class) GETSTRUCT(tuple);
9900
9901 /*
9902 * Since we copy the file directly without looking at the shared buffers,
9903 * we'd better first flush out any pages of the source relation that are
9904 * in shared buffers. We assume no new changes will be made while we are
9905 * holding exclusive lock on the rel.
9906 */
9907 FlushRelationBuffers(rel);
9908
9909 /*
9910 * Relfilenodes are not unique in databases across tablespaces, so we need
9911 * to allocate a new one in the new tablespace.
9912 */
9913 newrelfilenode = GetNewRelFileNode(newTableSpace, NULL,
9914 rel->rd_rel->relpersistence);
9915
9916 /* Open old and new relation */
9917 newrnode = rel->rd_node;
9918 newrnode.relNode = newrelfilenode;
9919 newrnode.spcNode = newTableSpace;
9920 dstrel = smgropen(newrnode, rel->rd_backend);
9921
9922 RelationOpenSmgr(rel);
9923
9924 /*
9925 * Create and copy all forks of the relation, and schedule unlinking of
9926 * old physical files.
9927 *
9928 * NOTE: any conflict in relfilenode value will be caught in
9929 * RelationCreateStorage().
9930 */
9931 RelationCreateStorage(newrnode, rel->rd_rel->relpersistence);
9932
9933 /* copy main fork */
9934 copy_relation_data(rel->rd_smgr, dstrel, MAIN_FORKNUM,
9935 rel->rd_rel->relpersistence);
9936
9937 /* copy those extra forks that exist */
9938 for (forkNum = MAIN_FORKNUM + 1; forkNum <= MAX_FORKNUM; forkNum++)
9939 {
9940 if (smgrexists(rel->rd_smgr, forkNum))
9941 {
9942 smgrcreate(dstrel, forkNum, false);
9943
9944 /*
9945 * WAL log creation if the relation is persistent, or this is the
9946 * init fork of an unlogged relation.
9947 */
9948 if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT ||
9949 (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
9950 forkNum == INIT_FORKNUM))
9951 log_smgrcreate(&newrnode, forkNum);
9952 copy_relation_data(rel->rd_smgr, dstrel, forkNum,
9953 rel->rd_rel->relpersistence);
9954 }
9955 }
9956
9957 /* drop old relation, and close new one */
9958 RelationDropStorage(rel);
9959 smgrclose(dstrel);
9960
9961 /* update the pg_class row */
9962 rd_rel->reltablespace = (newTableSpace == MyDatabaseTableSpace) ? InvalidOid : newTableSpace;
9963 rd_rel->relfilenode = newrelfilenode;
9964 simple_heap_update(pg_class, &tuple->t_self, tuple);
9965 CatalogUpdateIndexes(pg_class, tuple);
9966
9967 InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
9968
9969 heap_freetuple(tuple);
9970
9971 heap_close(pg_class, RowExclusiveLock);
9972
9973 relation_close(rel, NoLock);
9974
9975 /* Make sure the reltablespace change is visible */
9976 CommandCounterIncrement();
9977
9978 /* Move associated toast relation and/or indexes, too */
9979 if (OidIsValid(reltoastrelid))
9980 ATExecSetTableSpace(reltoastrelid, newTableSpace, lockmode);
9981 foreach(lc, reltoastidxids)
9982 ATExecSetTableSpace(lfirst_oid(lc), newTableSpace, lockmode);
9983
9984 /* Clean up */
9985 list_free(reltoastidxids);
9986 }
9987
9988 /*
9989 * Alter Table ALL ... SET TABLESPACE
9990 *
9991 * Allows a user to move all objects of some type in a given tablespace in the
9992 * current database to another tablespace. Objects can be chosen based on the
9993 * owner of the object also, to allow users to move only their objects.
9994 * The user must have CREATE rights on the new tablespace, as usual. The main
9995 * permissions handling is done by the lower-level table move function.
9996 *
9997 * All to-be-moved objects are locked first. If NOWAIT is specified and the
9998 * lock can't be acquired then we ereport(ERROR).
9999 */
10000 Oid
AlterTableMoveAll(AlterTableMoveAllStmt * stmt)10001 AlterTableMoveAll(AlterTableMoveAllStmt *stmt)
10002 {
10003 List *relations = NIL;
10004 ListCell *l;
10005 ScanKeyData key[1];
10006 Relation rel;
10007 HeapScanDesc scan;
10008 HeapTuple tuple;
10009 Oid orig_tablespaceoid;
10010 Oid new_tablespaceoid;
10011 List *role_oids = roleSpecsToIds(stmt->roles);
10012
10013 /* Ensure we were not asked to move something we can't */
10014 if (stmt->objtype != OBJECT_TABLE && stmt->objtype != OBJECT_INDEX &&
10015 stmt->objtype != OBJECT_MATVIEW)
10016 ereport(ERROR,
10017 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
10018 errmsg("only tables, indexes, and materialized views exist in tablespaces")));
10019
10020 /* Get the orig and new tablespace OIDs */
10021 orig_tablespaceoid = get_tablespace_oid(stmt->orig_tablespacename, false);
10022 new_tablespaceoid = get_tablespace_oid(stmt->new_tablespacename, false);
10023
10024 /* Can't move shared relations in to or out of pg_global */
10025 /* This is also checked by ATExecSetTableSpace, but nice to stop earlier */
10026 if (orig_tablespaceoid == GLOBALTABLESPACE_OID ||
10027 new_tablespaceoid == GLOBALTABLESPACE_OID)
10028 ereport(ERROR,
10029 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
10030 errmsg("cannot move relations in to or out of pg_global tablespace")));
10031
10032 /*
10033 * Must have CREATE rights on the new tablespace, unless it is the
10034 * database default tablespace (which all users implicitly have CREATE
10035 * rights on).
10036 */
10037 if (OidIsValid(new_tablespaceoid) && new_tablespaceoid != MyDatabaseTableSpace)
10038 {
10039 AclResult aclresult;
10040
10041 aclresult = pg_tablespace_aclcheck(new_tablespaceoid, GetUserId(),
10042 ACL_CREATE);
10043 if (aclresult != ACLCHECK_OK)
10044 aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
10045 get_tablespace_name(new_tablespaceoid));
10046 }
10047
10048 /*
10049 * Now that the checks are done, check if we should set either to
10050 * InvalidOid because it is our database's default tablespace.
10051 */
10052 if (orig_tablespaceoid == MyDatabaseTableSpace)
10053 orig_tablespaceoid = InvalidOid;
10054
10055 if (new_tablespaceoid == MyDatabaseTableSpace)
10056 new_tablespaceoid = InvalidOid;
10057
10058 /* no-op */
10059 if (orig_tablespaceoid == new_tablespaceoid)
10060 return new_tablespaceoid;
10061
10062 /*
10063 * Walk the list of objects in the tablespace and move them. This will
10064 * only find objects in our database, of course.
10065 */
10066 ScanKeyInit(&key[0],
10067 Anum_pg_class_reltablespace,
10068 BTEqualStrategyNumber, F_OIDEQ,
10069 ObjectIdGetDatum(orig_tablespaceoid));
10070
10071 rel = heap_open(RelationRelationId, AccessShareLock);
10072 scan = heap_beginscan_catalog(rel, 1, key);
10073 while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
10074 {
10075 Oid relOid = HeapTupleGetOid(tuple);
10076 Form_pg_class relForm;
10077
10078 relForm = (Form_pg_class) GETSTRUCT(tuple);
10079
10080 /*
10081 * Do not move objects in pg_catalog as part of this, if an admin
10082 * really wishes to do so, they can issue the individual ALTER
10083 * commands directly.
10084 *
10085 * Also, explicitly avoid any shared tables, temp tables, or TOAST
10086 * (TOAST will be moved with the main table).
10087 */
10088 if (IsSystemNamespace(relForm->relnamespace) || relForm->relisshared ||
10089 isAnyTempNamespace(relForm->relnamespace) ||
10090 relForm->relnamespace == PG_TOAST_NAMESPACE)
10091 continue;
10092
10093 /* Only move the object type requested */
10094 if ((stmt->objtype == OBJECT_TABLE &&
10095 relForm->relkind != RELKIND_RELATION) ||
10096 (stmt->objtype == OBJECT_INDEX &&
10097 relForm->relkind != RELKIND_INDEX) ||
10098 (stmt->objtype == OBJECT_MATVIEW &&
10099 relForm->relkind != RELKIND_MATVIEW))
10100 continue;
10101
10102 /* Check if we are only moving objects owned by certain roles */
10103 if (role_oids != NIL && !list_member_oid(role_oids, relForm->relowner))
10104 continue;
10105
10106 /*
10107 * Handle permissions-checking here since we are locking the tables
10108 * and also to avoid doing a bunch of work only to fail part-way. Note
10109 * that permissions will also be checked by AlterTableInternal().
10110 *
10111 * Caller must be considered an owner on the table to move it.
10112 */
10113 if (!pg_class_ownercheck(relOid, GetUserId()))
10114 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
10115 NameStr(relForm->relname));
10116
10117 if (stmt->nowait &&
10118 !ConditionalLockRelationOid(relOid, AccessExclusiveLock))
10119 ereport(ERROR,
10120 (errcode(ERRCODE_OBJECT_IN_USE),
10121 errmsg("aborting because lock on relation \"%s.%s\" is not available",
10122 get_namespace_name(relForm->relnamespace),
10123 NameStr(relForm->relname))));
10124 else
10125 LockRelationOid(relOid, AccessExclusiveLock);
10126
10127 /* Add to our list of objects to move */
10128 relations = lappend_oid(relations, relOid);
10129 }
10130
10131 heap_endscan(scan);
10132 heap_close(rel, AccessShareLock);
10133
10134 if (relations == NIL)
10135 ereport(NOTICE,
10136 (errcode(ERRCODE_NO_DATA_FOUND),
10137 errmsg("no matching relations in tablespace \"%s\" found",
10138 orig_tablespaceoid == InvalidOid ? "(database default)" :
10139 get_tablespace_name(orig_tablespaceoid))));
10140
10141 /* Everything is locked, loop through and move all of the relations. */
10142 foreach(l, relations)
10143 {
10144 List *cmds = NIL;
10145 AlterTableCmd *cmd = makeNode(AlterTableCmd);
10146
10147 cmd->subtype = AT_SetTableSpace;
10148 cmd->name = stmt->new_tablespacename;
10149
10150 cmds = lappend(cmds, cmd);
10151
10152 EventTriggerAlterTableStart((Node *) stmt);
10153 /* OID is set by AlterTableInternal */
10154 AlterTableInternal(lfirst_oid(l), cmds, false);
10155 EventTriggerAlterTableEnd();
10156 }
10157
10158 return new_tablespaceoid;
10159 }
10160
10161 /*
10162 * Copy data, block by block
10163 */
10164 static void
copy_relation_data(SMgrRelation src,SMgrRelation dst,ForkNumber forkNum,char relpersistence)10165 copy_relation_data(SMgrRelation src, SMgrRelation dst,
10166 ForkNumber forkNum, char relpersistence)
10167 {
10168 PGAlignedBlock buf;
10169 Page page;
10170 bool use_wal;
10171 bool copying_initfork;
10172 BlockNumber nblocks;
10173 BlockNumber blkno;
10174
10175 page = (Page) buf.data;
10176
10177 /*
10178 * The init fork for an unlogged relation in many respects has to be
10179 * treated the same as normal relation, changes need to be WAL logged and
10180 * it needs to be synced to disk.
10181 */
10182 copying_initfork = relpersistence == RELPERSISTENCE_UNLOGGED &&
10183 forkNum == INIT_FORKNUM;
10184
10185 /*
10186 * We need to log the copied data in WAL iff WAL archiving/streaming is
10187 * enabled AND it's a permanent relation.
10188 */
10189 use_wal = XLogIsNeeded() &&
10190 (relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork);
10191
10192 nblocks = smgrnblocks(src, forkNum);
10193
10194 for (blkno = 0; blkno < nblocks; blkno++)
10195 {
10196 /* If we got a cancel signal during the copy of the data, quit */
10197 CHECK_FOR_INTERRUPTS();
10198
10199 smgrread(src, forkNum, blkno, buf.data);
10200
10201 if (!PageIsVerified(page, blkno))
10202 ereport(ERROR,
10203 (errcode(ERRCODE_DATA_CORRUPTED),
10204 errmsg("invalid page in block %u of relation %s",
10205 blkno,
10206 relpathbackend(src->smgr_rnode.node,
10207 src->smgr_rnode.backend,
10208 forkNum))));
10209
10210 /*
10211 * WAL-log the copied page. Unfortunately we don't know what kind of a
10212 * page this is, so we have to log the full page including any unused
10213 * space.
10214 */
10215 if (use_wal)
10216 log_newpage(&dst->smgr_rnode.node, forkNum, blkno, page, false);
10217
10218 PageSetChecksumInplace(page, blkno);
10219
10220 /*
10221 * Now write the page. We say isTemp = true even if it's not a temp
10222 * rel, because there's no need for smgr to schedule an fsync for this
10223 * write; we'll do it ourselves below.
10224 */
10225 smgrextend(dst, forkNum, blkno, buf.data, true);
10226 }
10227
10228 /*
10229 * If the rel is WAL-logged, must fsync before commit. We use heap_sync
10230 * to ensure that the toast table gets fsync'd too. (For a temp or
10231 * unlogged rel we don't care since the data will be gone after a crash
10232 * anyway.)
10233 *
10234 * It's obvious that we must do this when not WAL-logging the copy. It's
10235 * less obvious that we have to do it even if we did WAL-log the copied
10236 * pages. The reason is that since we're copying outside shared buffers, a
10237 * CHECKPOINT occurring during the copy has no way to flush the previously
10238 * written data to disk (indeed it won't know the new rel even exists). A
10239 * crash later on would replay WAL from the checkpoint, therefore it
10240 * wouldn't replay our earlier WAL entries. If we do not fsync those pages
10241 * here, they might still not be on disk when the crash occurs.
10242 */
10243 if (relpersistence == RELPERSISTENCE_PERMANENT || copying_initfork)
10244 smgrimmedsync(dst, forkNum);
10245 }
10246
10247 /*
10248 * ALTER TABLE ENABLE/DISABLE TRIGGER
10249 *
10250 * We just pass this off to trigger.c.
10251 */
10252 static void
ATExecEnableDisableTrigger(Relation rel,char * trigname,char fires_when,bool skip_system,LOCKMODE lockmode)10253 ATExecEnableDisableTrigger(Relation rel, char *trigname,
10254 char fires_when, bool skip_system, LOCKMODE lockmode)
10255 {
10256 EnableDisableTrigger(rel, trigname, fires_when, skip_system);
10257 }
10258
10259 /*
10260 * ALTER TABLE ENABLE/DISABLE RULE
10261 *
10262 * We just pass this off to rewriteDefine.c.
10263 */
10264 static void
ATExecEnableDisableRule(Relation rel,char * trigname,char fires_when,LOCKMODE lockmode)10265 ATExecEnableDisableRule(Relation rel, char *trigname,
10266 char fires_when, LOCKMODE lockmode)
10267 {
10268 EnableDisableRule(rel, trigname, fires_when);
10269 }
10270
10271 /*
10272 * ALTER TABLE INHERIT
10273 *
10274 * Add a parent to the child's parents. This verifies that all the columns and
10275 * check constraints of the parent appear in the child and that they have the
10276 * same data types and expressions.
10277 */
10278 static void
ATPrepAddInherit(Relation child_rel)10279 ATPrepAddInherit(Relation child_rel)
10280 {
10281 if (child_rel->rd_rel->reloftype)
10282 ereport(ERROR,
10283 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
10284 errmsg("cannot change inheritance of typed table")));
10285 }
10286
10287 /*
10288 * Return the address of the new parent relation.
10289 */
10290 static ObjectAddress
ATExecAddInherit(Relation child_rel,RangeVar * parent,LOCKMODE lockmode)10291 ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode)
10292 {
10293 Relation parent_rel,
10294 catalogRelation;
10295 SysScanDesc scan;
10296 ScanKeyData key;
10297 HeapTuple inheritsTuple;
10298 int32 inhseqno;
10299 List *children;
10300 ObjectAddress address;
10301
10302 /*
10303 * A self-exclusive lock is needed here. See the similar case in
10304 * MergeAttributes() for a full explanation.
10305 */
10306 parent_rel = heap_openrv(parent, ShareUpdateExclusiveLock);
10307
10308 /*
10309 * Must be owner of both parent and child -- child was checked by
10310 * ATSimplePermissions call in ATPrepCmd
10311 */
10312 ATSimplePermissions(parent_rel, ATT_TABLE | ATT_FOREIGN_TABLE);
10313
10314 /* Permanent rels cannot inherit from temporary ones */
10315 if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
10316 child_rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
10317 ereport(ERROR,
10318 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
10319 errmsg("cannot inherit from temporary relation \"%s\"",
10320 RelationGetRelationName(parent_rel))));
10321
10322 /* If parent rel is temp, it must belong to this session */
10323 if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
10324 !parent_rel->rd_islocaltemp)
10325 ereport(ERROR,
10326 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
10327 errmsg("cannot inherit from temporary relation of another session")));
10328
10329 /* Ditto for the child */
10330 if (child_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
10331 !child_rel->rd_islocaltemp)
10332 ereport(ERROR,
10333 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
10334 errmsg("cannot inherit to temporary relation of another session")));
10335
10336 /*
10337 * Check for duplicates in the list of parents, and determine the highest
10338 * inhseqno already present; we'll use the next one for the new parent.
10339 * (Note: get RowExclusiveLock because we will write pg_inherits below.)
10340 *
10341 * Note: we do not reject the case where the child already inherits from
10342 * the parent indirectly; CREATE TABLE doesn't reject comparable cases.
10343 */
10344 catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock);
10345 ScanKeyInit(&key,
10346 Anum_pg_inherits_inhrelid,
10347 BTEqualStrategyNumber, F_OIDEQ,
10348 ObjectIdGetDatum(RelationGetRelid(child_rel)));
10349 scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
10350 true, NULL, 1, &key);
10351
10352 /* inhseqno sequences start at 1 */
10353 inhseqno = 0;
10354 while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
10355 {
10356 Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inheritsTuple);
10357
10358 if (inh->inhparent == RelationGetRelid(parent_rel))
10359 ereport(ERROR,
10360 (errcode(ERRCODE_DUPLICATE_TABLE),
10361 errmsg("relation \"%s\" would be inherited from more than once",
10362 RelationGetRelationName(parent_rel))));
10363 if (inh->inhseqno > inhseqno)
10364 inhseqno = inh->inhseqno;
10365 }
10366 systable_endscan(scan);
10367
10368 /*
10369 * Prevent circularity by seeing if proposed parent inherits from child.
10370 * (In particular, this disallows making a rel inherit from itself.)
10371 *
10372 * This is not completely bulletproof because of race conditions: in
10373 * multi-level inheritance trees, someone else could concurrently be
10374 * making another inheritance link that closes the loop but does not join
10375 * either of the rels we have locked. Preventing that seems to require
10376 * exclusive locks on the entire inheritance tree, which is a cure worse
10377 * than the disease. find_all_inheritors() will cope with circularity
10378 * anyway, so don't sweat it too much.
10379 *
10380 * We use weakest lock we can on child's children, namely AccessShareLock.
10381 */
10382 children = find_all_inheritors(RelationGetRelid(child_rel),
10383 AccessShareLock, NULL);
10384
10385 if (list_member_oid(children, RelationGetRelid(parent_rel)))
10386 ereport(ERROR,
10387 (errcode(ERRCODE_DUPLICATE_TABLE),
10388 errmsg("circular inheritance not allowed"),
10389 errdetail("\"%s\" is already a child of \"%s\".",
10390 parent->relname,
10391 RelationGetRelationName(child_rel))));
10392
10393 /* If parent has OIDs then child must have OIDs */
10394 if (parent_rel->rd_rel->relhasoids && !child_rel->rd_rel->relhasoids)
10395 ereport(ERROR,
10396 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
10397 errmsg("table \"%s\" without OIDs cannot inherit from table \"%s\" with OIDs",
10398 RelationGetRelationName(child_rel),
10399 RelationGetRelationName(parent_rel))));
10400
10401 /* Match up the columns and bump attinhcount as needed */
10402 MergeAttributesIntoExisting(child_rel, parent_rel);
10403
10404 /* Match up the constraints and bump coninhcount as needed */
10405 MergeConstraintsIntoExisting(child_rel, parent_rel);
10406
10407 /*
10408 * OK, it looks valid. Make the catalog entries that show inheritance.
10409 */
10410 StoreCatalogInheritance1(RelationGetRelid(child_rel),
10411 RelationGetRelid(parent_rel),
10412 inhseqno + 1,
10413 catalogRelation);
10414
10415 ObjectAddressSet(address, RelationRelationId,
10416 RelationGetRelid(parent_rel));
10417
10418 /* Now we're done with pg_inherits */
10419 heap_close(catalogRelation, RowExclusiveLock);
10420
10421 /* keep our lock on the parent relation until commit */
10422 heap_close(parent_rel, NoLock);
10423
10424 return address;
10425 }
10426
10427 /*
10428 * Obtain the source-text form of the constraint expression for a check
10429 * constraint, given its pg_constraint tuple
10430 */
10431 static char *
decompile_conbin(HeapTuple contup,TupleDesc tupdesc)10432 decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
10433 {
10434 Form_pg_constraint con;
10435 bool isnull;
10436 Datum attr;
10437 Datum expr;
10438
10439 con = (Form_pg_constraint) GETSTRUCT(contup);
10440 attr = heap_getattr(contup, Anum_pg_constraint_conbin, tupdesc, &isnull);
10441 if (isnull)
10442 elog(ERROR, "null conbin for constraint %u", HeapTupleGetOid(contup));
10443
10444 expr = DirectFunctionCall2(pg_get_expr, attr,
10445 ObjectIdGetDatum(con->conrelid));
10446 return TextDatumGetCString(expr);
10447 }
10448
10449 /*
10450 * Determine whether two check constraints are functionally equivalent
10451 *
10452 * The test we apply is to see whether they reverse-compile to the same
10453 * source string. This insulates us from issues like whether attributes
10454 * have the same physical column numbers in parent and child relations.
10455 */
10456 static bool
constraints_equivalent(HeapTuple a,HeapTuple b,TupleDesc tupleDesc)10457 constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc)
10458 {
10459 Form_pg_constraint acon = (Form_pg_constraint) GETSTRUCT(a);
10460 Form_pg_constraint bcon = (Form_pg_constraint) GETSTRUCT(b);
10461
10462 if (acon->condeferrable != bcon->condeferrable ||
10463 acon->condeferred != bcon->condeferred ||
10464 strcmp(decompile_conbin(a, tupleDesc),
10465 decompile_conbin(b, tupleDesc)) != 0)
10466 return false;
10467 else
10468 return true;
10469 }
10470
10471 /*
10472 * Check columns in child table match up with columns in parent, and increment
10473 * their attinhcount.
10474 *
10475 * Called by ATExecAddInherit
10476 *
10477 * Currently all parent columns must be found in child. Missing columns are an
10478 * error. One day we might consider creating new columns like CREATE TABLE
10479 * does. However, that is widely unpopular --- in the common use case of
10480 * partitioned tables it's a foot-gun.
10481 *
10482 * The data type must match exactly. If the parent column is NOT NULL then
10483 * the child must be as well. Defaults are not compared, however.
10484 */
10485 static void
MergeAttributesIntoExisting(Relation child_rel,Relation parent_rel)10486 MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel)
10487 {
10488 Relation attrrel;
10489 AttrNumber parent_attno;
10490 int parent_natts;
10491 TupleDesc tupleDesc;
10492 HeapTuple tuple;
10493
10494 attrrel = heap_open(AttributeRelationId, RowExclusiveLock);
10495
10496 tupleDesc = RelationGetDescr(parent_rel);
10497 parent_natts = tupleDesc->natts;
10498
10499 for (parent_attno = 1; parent_attno <= parent_natts; parent_attno++)
10500 {
10501 Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1];
10502 char *attributeName = NameStr(attribute->attname);
10503
10504 /* Ignore dropped columns in the parent. */
10505 if (attribute->attisdropped)
10506 continue;
10507
10508 /* Find same column in child (matching on column name). */
10509 tuple = SearchSysCacheCopyAttName(RelationGetRelid(child_rel),
10510 attributeName);
10511 if (HeapTupleIsValid(tuple))
10512 {
10513 /* Check they are same type, typmod, and collation */
10514 Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
10515
10516 if (attribute->atttypid != childatt->atttypid ||
10517 attribute->atttypmod != childatt->atttypmod)
10518 ereport(ERROR,
10519 (errcode(ERRCODE_DATATYPE_MISMATCH),
10520 errmsg("child table \"%s\" has different type for column \"%s\"",
10521 RelationGetRelationName(child_rel),
10522 attributeName)));
10523
10524 if (attribute->attcollation != childatt->attcollation)
10525 ereport(ERROR,
10526 (errcode(ERRCODE_COLLATION_MISMATCH),
10527 errmsg("child table \"%s\" has different collation for column \"%s\"",
10528 RelationGetRelationName(child_rel),
10529 attributeName)));
10530
10531 /*
10532 * Check child doesn't discard NOT NULL property. (Other
10533 * constraints are checked elsewhere.)
10534 */
10535 if (attribute->attnotnull && !childatt->attnotnull)
10536 ereport(ERROR,
10537 (errcode(ERRCODE_DATATYPE_MISMATCH),
10538 errmsg("column \"%s\" in child table must be marked NOT NULL",
10539 attributeName)));
10540
10541 /*
10542 * OK, bump the child column's inheritance count. (If we fail
10543 * later on, this change will just roll back.)
10544 */
10545 childatt->attinhcount++;
10546 simple_heap_update(attrrel, &tuple->t_self, tuple);
10547 CatalogUpdateIndexes(attrrel, tuple);
10548 heap_freetuple(tuple);
10549 }
10550 else
10551 {
10552 ereport(ERROR,
10553 (errcode(ERRCODE_DATATYPE_MISMATCH),
10554 errmsg("child table is missing column \"%s\"",
10555 attributeName)));
10556 }
10557 }
10558
10559 /*
10560 * If the parent has an OID column, so must the child, and we'd better
10561 * update the child's attinhcount and attislocal the same as for normal
10562 * columns. We needn't check data type or not-nullness though.
10563 */
10564 if (tupleDesc->tdhasoid)
10565 {
10566 /*
10567 * Here we match by column number not name; the match *must* be the
10568 * system column, not some random column named "oid".
10569 */
10570 tuple = SearchSysCacheCopy2(ATTNUM,
10571 ObjectIdGetDatum(RelationGetRelid(child_rel)),
10572 Int16GetDatum(ObjectIdAttributeNumber));
10573 if (HeapTupleIsValid(tuple))
10574 {
10575 Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
10576
10577 /* See comments above; these changes should be the same */
10578 childatt->attinhcount++;
10579 simple_heap_update(attrrel, &tuple->t_self, tuple);
10580 CatalogUpdateIndexes(attrrel, tuple);
10581 heap_freetuple(tuple);
10582 }
10583 else
10584 {
10585 ereport(ERROR,
10586 (errcode(ERRCODE_DATATYPE_MISMATCH),
10587 errmsg("child table is missing column \"%s\"",
10588 "oid")));
10589 }
10590 }
10591
10592 heap_close(attrrel, RowExclusiveLock);
10593 }
10594
10595 /*
10596 * Check constraints in child table match up with constraints in parent,
10597 * and increment their coninhcount.
10598 *
10599 * Constraints that are marked ONLY in the parent are ignored.
10600 *
10601 * Called by ATExecAddInherit
10602 *
10603 * Currently all constraints in parent must be present in the child. One day we
10604 * may consider adding new constraints like CREATE TABLE does.
10605 *
10606 * XXX This is O(N^2) which may be an issue with tables with hundreds of
10607 * constraints. As long as tables have more like 10 constraints it shouldn't be
10608 * a problem though. Even 100 constraints ought not be the end of the world.
10609 *
10610 * XXX See MergeWithExistingConstraint too if you change this code.
10611 */
10612 static void
MergeConstraintsIntoExisting(Relation child_rel,Relation parent_rel)10613 MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel)
10614 {
10615 Relation catalog_relation;
10616 TupleDesc tuple_desc;
10617 SysScanDesc parent_scan;
10618 ScanKeyData parent_key;
10619 HeapTuple parent_tuple;
10620
10621 catalog_relation = heap_open(ConstraintRelationId, RowExclusiveLock);
10622 tuple_desc = RelationGetDescr(catalog_relation);
10623
10624 /* Outer loop scans through the parent's constraint definitions */
10625 ScanKeyInit(&parent_key,
10626 Anum_pg_constraint_conrelid,
10627 BTEqualStrategyNumber, F_OIDEQ,
10628 ObjectIdGetDatum(RelationGetRelid(parent_rel)));
10629 parent_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId,
10630 true, NULL, 1, &parent_key);
10631
10632 while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan)))
10633 {
10634 Form_pg_constraint parent_con = (Form_pg_constraint) GETSTRUCT(parent_tuple);
10635 SysScanDesc child_scan;
10636 ScanKeyData child_key;
10637 HeapTuple child_tuple;
10638 bool found = false;
10639
10640 if (parent_con->contype != CONSTRAINT_CHECK)
10641 continue;
10642
10643 /* if the parent's constraint is marked NO INHERIT, it's not inherited */
10644 if (parent_con->connoinherit)
10645 continue;
10646
10647 /* Search for a child constraint matching this one */
10648 ScanKeyInit(&child_key,
10649 Anum_pg_constraint_conrelid,
10650 BTEqualStrategyNumber, F_OIDEQ,
10651 ObjectIdGetDatum(RelationGetRelid(child_rel)));
10652 child_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId,
10653 true, NULL, 1, &child_key);
10654
10655 while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan)))
10656 {
10657 Form_pg_constraint child_con = (Form_pg_constraint) GETSTRUCT(child_tuple);
10658 HeapTuple child_copy;
10659
10660 if (child_con->contype != CONSTRAINT_CHECK)
10661 continue;
10662
10663 if (strcmp(NameStr(parent_con->conname),
10664 NameStr(child_con->conname)) != 0)
10665 continue;
10666
10667 if (!constraints_equivalent(parent_tuple, child_tuple, tuple_desc))
10668 ereport(ERROR,
10669 (errcode(ERRCODE_DATATYPE_MISMATCH),
10670 errmsg("child table \"%s\" has different definition for check constraint \"%s\"",
10671 RelationGetRelationName(child_rel),
10672 NameStr(parent_con->conname))));
10673
10674 /* If the child constraint is "no inherit" then cannot merge */
10675 if (child_con->connoinherit)
10676 ereport(ERROR,
10677 (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
10678 errmsg("constraint \"%s\" conflicts with non-inherited constraint on child table \"%s\"",
10679 NameStr(child_con->conname),
10680 RelationGetRelationName(child_rel))));
10681
10682 /*
10683 * If the child constraint is "not valid" then cannot merge with a
10684 * valid parent constraint
10685 */
10686 if (parent_con->convalidated && !child_con->convalidated)
10687 ereport(ERROR,
10688 (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
10689 errmsg("constraint \"%s\" conflicts with NOT VALID constraint on child table \"%s\"",
10690 NameStr(child_con->conname),
10691 RelationGetRelationName(child_rel))));
10692
10693 /*
10694 * OK, bump the child constraint's inheritance count. (If we fail
10695 * later on, this change will just roll back.)
10696 */
10697 child_copy = heap_copytuple(child_tuple);
10698 child_con = (Form_pg_constraint) GETSTRUCT(child_copy);
10699 child_con->coninhcount++;
10700 simple_heap_update(catalog_relation, &child_copy->t_self, child_copy);
10701 CatalogUpdateIndexes(catalog_relation, child_copy);
10702 heap_freetuple(child_copy);
10703
10704 found = true;
10705 break;
10706 }
10707
10708 systable_endscan(child_scan);
10709
10710 if (!found)
10711 ereport(ERROR,
10712 (errcode(ERRCODE_DATATYPE_MISMATCH),
10713 errmsg("child table is missing constraint \"%s\"",
10714 NameStr(parent_con->conname))));
10715 }
10716
10717 systable_endscan(parent_scan);
10718 heap_close(catalog_relation, RowExclusiveLock);
10719 }
10720
10721 /*
10722 * ALTER TABLE NO INHERIT
10723 *
10724 * Drop a parent from the child's parents. This just adjusts the attinhcount
10725 * and attislocal of the columns and removes the pg_inherit and pg_depend
10726 * entries.
10727 *
10728 * If attinhcount goes to 0 then attislocal gets set to true. If it goes back
10729 * up attislocal stays true, which means if a child is ever removed from a
10730 * parent then its columns will never be automatically dropped which may
10731 * surprise. But at least we'll never surprise by dropping columns someone
10732 * isn't expecting to be dropped which would actually mean data loss.
10733 *
10734 * coninhcount and conislocal for inherited constraints are adjusted in
10735 * exactly the same way.
10736 *
10737 * Return value is the address of the relation that is no longer parent.
10738 */
10739 static ObjectAddress
ATExecDropInherit(Relation rel,RangeVar * parent,LOCKMODE lockmode)10740 ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
10741 {
10742 Relation parent_rel;
10743 Oid parent_oid;
10744 Relation catalogRelation;
10745 SysScanDesc scan;
10746 ScanKeyData key[3];
10747 HeapTuple inheritsTuple,
10748 attributeTuple,
10749 constraintTuple;
10750 List *connames;
10751 bool found = false;
10752 ObjectAddress address;
10753
10754 /*
10755 * AccessShareLock on the parent is probably enough, seeing that DROP
10756 * TABLE doesn't lock parent tables at all. We need some lock since we'll
10757 * be inspecting the parent's schema.
10758 */
10759 parent_rel = heap_openrv(parent, AccessShareLock);
10760
10761 /*
10762 * We don't bother to check ownership of the parent table --- ownership of
10763 * the child is presumed enough rights.
10764 */
10765
10766 /*
10767 * Find and destroy the pg_inherits entry linking the two, or error out if
10768 * there is none.
10769 */
10770 catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock);
10771 ScanKeyInit(&key[0],
10772 Anum_pg_inherits_inhrelid,
10773 BTEqualStrategyNumber, F_OIDEQ,
10774 ObjectIdGetDatum(RelationGetRelid(rel)));
10775 scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
10776 true, NULL, 1, key);
10777
10778 while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
10779 {
10780 Oid inhparent;
10781
10782 inhparent = ((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhparent;
10783 if (inhparent == RelationGetRelid(parent_rel))
10784 {
10785 simple_heap_delete(catalogRelation, &inheritsTuple->t_self);
10786 found = true;
10787 break;
10788 }
10789 }
10790
10791 systable_endscan(scan);
10792 heap_close(catalogRelation, RowExclusiveLock);
10793
10794 if (!found)
10795 ereport(ERROR,
10796 (errcode(ERRCODE_UNDEFINED_TABLE),
10797 errmsg("relation \"%s\" is not a parent of relation \"%s\"",
10798 RelationGetRelationName(parent_rel),
10799 RelationGetRelationName(rel))));
10800
10801 /*
10802 * Search through child columns looking for ones matching parent rel
10803 */
10804 catalogRelation = heap_open(AttributeRelationId, RowExclusiveLock);
10805 ScanKeyInit(&key[0],
10806 Anum_pg_attribute_attrelid,
10807 BTEqualStrategyNumber, F_OIDEQ,
10808 ObjectIdGetDatum(RelationGetRelid(rel)));
10809 scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId,
10810 true, NULL, 1, key);
10811 while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
10812 {
10813 Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
10814
10815 /* Ignore if dropped or not inherited */
10816 if (att->attisdropped)
10817 continue;
10818 if (att->attinhcount <= 0)
10819 continue;
10820
10821 if (SearchSysCacheExistsAttName(RelationGetRelid(parent_rel),
10822 NameStr(att->attname)))
10823 {
10824 /* Decrement inhcount and possibly set islocal to true */
10825 HeapTuple copyTuple = heap_copytuple(attributeTuple);
10826 Form_pg_attribute copy_att = (Form_pg_attribute) GETSTRUCT(copyTuple);
10827
10828 copy_att->attinhcount--;
10829 if (copy_att->attinhcount == 0)
10830 copy_att->attislocal = true;
10831
10832 simple_heap_update(catalogRelation, ©Tuple->t_self, copyTuple);
10833 CatalogUpdateIndexes(catalogRelation, copyTuple);
10834 heap_freetuple(copyTuple);
10835 }
10836 }
10837 systable_endscan(scan);
10838 heap_close(catalogRelation, RowExclusiveLock);
10839
10840 /*
10841 * Likewise, find inherited check constraints and disinherit them. To do
10842 * this, we first need a list of the names of the parent's check
10843 * constraints. (We cheat a bit by only checking for name matches,
10844 * assuming that the expressions will match.)
10845 */
10846 catalogRelation = heap_open(ConstraintRelationId, RowExclusiveLock);
10847 ScanKeyInit(&key[0],
10848 Anum_pg_constraint_conrelid,
10849 BTEqualStrategyNumber, F_OIDEQ,
10850 ObjectIdGetDatum(RelationGetRelid(parent_rel)));
10851 scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId,
10852 true, NULL, 1, key);
10853
10854 connames = NIL;
10855
10856 while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
10857 {
10858 Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
10859
10860 if (con->contype == CONSTRAINT_CHECK)
10861 connames = lappend(connames, pstrdup(NameStr(con->conname)));
10862 }
10863
10864 systable_endscan(scan);
10865
10866 /* Now scan the child's constraints */
10867 ScanKeyInit(&key[0],
10868 Anum_pg_constraint_conrelid,
10869 BTEqualStrategyNumber, F_OIDEQ,
10870 ObjectIdGetDatum(RelationGetRelid(rel)));
10871 scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId,
10872 true, NULL, 1, key);
10873
10874 while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
10875 {
10876 Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
10877 bool match;
10878 ListCell *lc;
10879
10880 if (con->contype != CONSTRAINT_CHECK)
10881 continue;
10882
10883 match = false;
10884 foreach(lc, connames)
10885 {
10886 if (strcmp(NameStr(con->conname), (char *) lfirst(lc)) == 0)
10887 {
10888 match = true;
10889 break;
10890 }
10891 }
10892
10893 if (match)
10894 {
10895 /* Decrement inhcount and possibly set islocal to true */
10896 HeapTuple copyTuple = heap_copytuple(constraintTuple);
10897 Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
10898
10899 if (copy_con->coninhcount <= 0) /* shouldn't happen */
10900 elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
10901 RelationGetRelid(rel), NameStr(copy_con->conname));
10902
10903 copy_con->coninhcount--;
10904 if (copy_con->coninhcount == 0)
10905 copy_con->conislocal = true;
10906
10907 simple_heap_update(catalogRelation, ©Tuple->t_self, copyTuple);
10908 CatalogUpdateIndexes(catalogRelation, copyTuple);
10909 heap_freetuple(copyTuple);
10910 }
10911 }
10912
10913 parent_oid = RelationGetRelid(parent_rel);
10914
10915 systable_endscan(scan);
10916 heap_close(catalogRelation, RowExclusiveLock);
10917
10918 drop_parent_dependency(RelationGetRelid(rel),
10919 RelationRelationId,
10920 RelationGetRelid(parent_rel));
10921
10922 /*
10923 * Post alter hook of this inherits. Since object_access_hook doesn't take
10924 * multiple object identifiers, we relay oid of parent relation using
10925 * auxiliary_id argument.
10926 */
10927 InvokeObjectPostAlterHookArg(InheritsRelationId,
10928 RelationGetRelid(rel), 0,
10929 RelationGetRelid(parent_rel), false);
10930
10931 /* keep our lock on the parent relation until commit */
10932 heap_close(parent_rel, NoLock);
10933
10934 ObjectAddressSet(address, RelationRelationId, parent_oid);
10935
10936 return address;
10937 }
10938
10939 /*
10940 * Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE
10941 * INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or
10942 * heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will
10943 * be TypeRelationId). There's no convenient way to do this, so go trawling
10944 * through pg_depend.
10945 */
10946 static void
drop_parent_dependency(Oid relid,Oid refclassid,Oid refobjid)10947 drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid)
10948 {
10949 Relation catalogRelation;
10950 SysScanDesc scan;
10951 ScanKeyData key[3];
10952 HeapTuple depTuple;
10953
10954 catalogRelation = heap_open(DependRelationId, RowExclusiveLock);
10955
10956 ScanKeyInit(&key[0],
10957 Anum_pg_depend_classid,
10958 BTEqualStrategyNumber, F_OIDEQ,
10959 ObjectIdGetDatum(RelationRelationId));
10960 ScanKeyInit(&key[1],
10961 Anum_pg_depend_objid,
10962 BTEqualStrategyNumber, F_OIDEQ,
10963 ObjectIdGetDatum(relid));
10964 ScanKeyInit(&key[2],
10965 Anum_pg_depend_objsubid,
10966 BTEqualStrategyNumber, F_INT4EQ,
10967 Int32GetDatum(0));
10968
10969 scan = systable_beginscan(catalogRelation, DependDependerIndexId, true,
10970 NULL, 3, key);
10971
10972 while (HeapTupleIsValid(depTuple = systable_getnext(scan)))
10973 {
10974 Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple);
10975
10976 if (dep->refclassid == refclassid &&
10977 dep->refobjid == refobjid &&
10978 dep->refobjsubid == 0 &&
10979 dep->deptype == DEPENDENCY_NORMAL)
10980 simple_heap_delete(catalogRelation, &depTuple->t_self);
10981 }
10982
10983 systable_endscan(scan);
10984 heap_close(catalogRelation, RowExclusiveLock);
10985 }
10986
10987 /*
10988 * ALTER TABLE OF
10989 *
10990 * Attach a table to a composite type, as though it had been created with CREATE
10991 * TABLE OF. All attname, atttypid, atttypmod and attcollation must match. The
10992 * subject table must not have inheritance parents. These restrictions ensure
10993 * that you cannot create a configuration impossible with CREATE TABLE OF alone.
10994 *
10995 * The address of the type is returned.
10996 */
10997 static ObjectAddress
ATExecAddOf(Relation rel,const TypeName * ofTypename,LOCKMODE lockmode)10998 ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
10999 {
11000 Oid relid = RelationGetRelid(rel);
11001 Type typetuple;
11002 Oid typeid;
11003 Relation inheritsRelation,
11004 relationRelation;
11005 SysScanDesc scan;
11006 ScanKeyData key;
11007 AttrNumber table_attno,
11008 type_attno;
11009 TupleDesc typeTupleDesc,
11010 tableTupleDesc;
11011 ObjectAddress tableobj,
11012 typeobj;
11013 HeapTuple classtuple;
11014
11015 /* Validate the type. */
11016 typetuple = typenameType(NULL, ofTypename, NULL);
11017 check_of_type(typetuple);
11018 typeid = HeapTupleGetOid(typetuple);
11019
11020 /* Fail if the table has any inheritance parents. */
11021 inheritsRelation = heap_open(InheritsRelationId, AccessShareLock);
11022 ScanKeyInit(&key,
11023 Anum_pg_inherits_inhrelid,
11024 BTEqualStrategyNumber, F_OIDEQ,
11025 ObjectIdGetDatum(relid));
11026 scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId,
11027 true, NULL, 1, &key);
11028 if (HeapTupleIsValid(systable_getnext(scan)))
11029 ereport(ERROR,
11030 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
11031 errmsg("typed tables cannot inherit")));
11032 systable_endscan(scan);
11033 heap_close(inheritsRelation, AccessShareLock);
11034
11035 /*
11036 * Check the tuple descriptors for compatibility. Unlike inheritance, we
11037 * require that the order also match. However, attnotnull need not match.
11038 * Also unlike inheritance, we do not require matching relhasoids.
11039 */
11040 typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1);
11041 tableTupleDesc = RelationGetDescr(rel);
11042 table_attno = 1;
11043 for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++)
11044 {
11045 Form_pg_attribute type_attr,
11046 table_attr;
11047 const char *type_attname,
11048 *table_attname;
11049
11050 /* Get the next non-dropped type attribute. */
11051 type_attr = typeTupleDesc->attrs[type_attno - 1];
11052 if (type_attr->attisdropped)
11053 continue;
11054 type_attname = NameStr(type_attr->attname);
11055
11056 /* Get the next non-dropped table attribute. */
11057 do
11058 {
11059 if (table_attno > tableTupleDesc->natts)
11060 ereport(ERROR,
11061 (errcode(ERRCODE_DATATYPE_MISMATCH),
11062 errmsg("table is missing column \"%s\"",
11063 type_attname)));
11064 table_attr = tableTupleDesc->attrs[table_attno++ - 1];
11065 } while (table_attr->attisdropped);
11066 table_attname = NameStr(table_attr->attname);
11067
11068 /* Compare name. */
11069 if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0)
11070 ereport(ERROR,
11071 (errcode(ERRCODE_DATATYPE_MISMATCH),
11072 errmsg("table has column \"%s\" where type requires \"%s\"",
11073 table_attname, type_attname)));
11074
11075 /* Compare type. */
11076 if (table_attr->atttypid != type_attr->atttypid ||
11077 table_attr->atttypmod != type_attr->atttypmod ||
11078 table_attr->attcollation != type_attr->attcollation)
11079 ereport(ERROR,
11080 (errcode(ERRCODE_DATATYPE_MISMATCH),
11081 errmsg("table \"%s\" has different type for column \"%s\"",
11082 RelationGetRelationName(rel), type_attname)));
11083 }
11084 DecrTupleDescRefCount(typeTupleDesc);
11085
11086 /* Any remaining columns at the end of the table had better be dropped. */
11087 for (; table_attno <= tableTupleDesc->natts; table_attno++)
11088 {
11089 Form_pg_attribute table_attr = tableTupleDesc->attrs[table_attno - 1];
11090
11091 if (!table_attr->attisdropped)
11092 ereport(ERROR,
11093 (errcode(ERRCODE_DATATYPE_MISMATCH),
11094 errmsg("table has extra column \"%s\"",
11095 NameStr(table_attr->attname))));
11096 }
11097
11098 /* If the table was already typed, drop the existing dependency. */
11099 if (rel->rd_rel->reloftype)
11100 drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype);
11101
11102 /* Record a dependency on the new type. */
11103 tableobj.classId = RelationRelationId;
11104 tableobj.objectId = relid;
11105 tableobj.objectSubId = 0;
11106 typeobj.classId = TypeRelationId;
11107 typeobj.objectId = typeid;
11108 typeobj.objectSubId = 0;
11109 recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL);
11110
11111 /* Update pg_class.reloftype */
11112 relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
11113 classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
11114 if (!HeapTupleIsValid(classtuple))
11115 elog(ERROR, "cache lookup failed for relation %u", relid);
11116 ((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid;
11117 simple_heap_update(relationRelation, &classtuple->t_self, classtuple);
11118 CatalogUpdateIndexes(relationRelation, classtuple);
11119
11120 InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
11121
11122 heap_freetuple(classtuple);
11123 heap_close(relationRelation, RowExclusiveLock);
11124
11125 ReleaseSysCache(typetuple);
11126
11127 return typeobj;
11128 }
11129
11130 /*
11131 * ALTER TABLE NOT OF
11132 *
11133 * Detach a typed table from its originating type. Just clear reloftype and
11134 * remove the dependency.
11135 */
11136 static void
ATExecDropOf(Relation rel,LOCKMODE lockmode)11137 ATExecDropOf(Relation rel, LOCKMODE lockmode)
11138 {
11139 Oid relid = RelationGetRelid(rel);
11140 Relation relationRelation;
11141 HeapTuple tuple;
11142
11143 if (!OidIsValid(rel->rd_rel->reloftype))
11144 ereport(ERROR,
11145 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
11146 errmsg("\"%s\" is not a typed table",
11147 RelationGetRelationName(rel))));
11148
11149 /*
11150 * We don't bother to check ownership of the type --- ownership of the
11151 * table is presumed enough rights. No lock required on the type, either.
11152 */
11153
11154 drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype);
11155
11156 /* Clear pg_class.reloftype */
11157 relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
11158 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
11159 if (!HeapTupleIsValid(tuple))
11160 elog(ERROR, "cache lookup failed for relation %u", relid);
11161 ((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid;
11162 simple_heap_update(relationRelation, &tuple->t_self, tuple);
11163 CatalogUpdateIndexes(relationRelation, tuple);
11164
11165 InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
11166
11167 heap_freetuple(tuple);
11168 heap_close(relationRelation, RowExclusiveLock);
11169 }
11170
11171 /*
11172 * relation_mark_replica_identity: Update a table's replica identity
11173 *
11174 * Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable
11175 * index. Otherwise, it should be InvalidOid.
11176 */
11177 static void
relation_mark_replica_identity(Relation rel,char ri_type,Oid indexOid,bool is_internal)11178 relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid,
11179 bool is_internal)
11180 {
11181 Relation pg_index;
11182 Relation pg_class;
11183 HeapTuple pg_class_tuple;
11184 HeapTuple pg_index_tuple;
11185 Form_pg_class pg_class_form;
11186 Form_pg_index pg_index_form;
11187
11188 ListCell *index;
11189
11190 /*
11191 * Check whether relreplident has changed, and update it if so.
11192 */
11193 pg_class = heap_open(RelationRelationId, RowExclusiveLock);
11194 pg_class_tuple = SearchSysCacheCopy1(RELOID,
11195 ObjectIdGetDatum(RelationGetRelid(rel)));
11196 if (!HeapTupleIsValid(pg_class_tuple))
11197 elog(ERROR, "cache lookup failed for relation \"%s\"",
11198 RelationGetRelationName(rel));
11199 pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple);
11200 if (pg_class_form->relreplident != ri_type)
11201 {
11202 pg_class_form->relreplident = ri_type;
11203 simple_heap_update(pg_class, &pg_class_tuple->t_self, pg_class_tuple);
11204 CatalogUpdateIndexes(pg_class, pg_class_tuple);
11205 }
11206 heap_close(pg_class, RowExclusiveLock);
11207 heap_freetuple(pg_class_tuple);
11208
11209 /*
11210 * Check whether the correct index is marked indisreplident; if so, we're
11211 * done.
11212 */
11213 if (OidIsValid(indexOid))
11214 {
11215 Assert(ri_type == REPLICA_IDENTITY_INDEX);
11216
11217 pg_index_tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexOid));
11218 if (!HeapTupleIsValid(pg_index_tuple))
11219 elog(ERROR, "cache lookup failed for index %u", indexOid);
11220 pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
11221
11222 if (pg_index_form->indisreplident)
11223 {
11224 ReleaseSysCache(pg_index_tuple);
11225 return;
11226 }
11227 ReleaseSysCache(pg_index_tuple);
11228 }
11229
11230 /*
11231 * Clear the indisreplident flag from any index that had it previously,
11232 * and set it for any index that should have it now.
11233 */
11234 pg_index = heap_open(IndexRelationId, RowExclusiveLock);
11235 foreach(index, RelationGetIndexList(rel))
11236 {
11237 Oid thisIndexOid = lfirst_oid(index);
11238 bool dirty = false;
11239
11240 pg_index_tuple = SearchSysCacheCopy1(INDEXRELID,
11241 ObjectIdGetDatum(thisIndexOid));
11242 if (!HeapTupleIsValid(pg_index_tuple))
11243 elog(ERROR, "cache lookup failed for index %u", thisIndexOid);
11244 pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
11245
11246 /*
11247 * Unset the bit if set. We know it's wrong because we checked this
11248 * earlier.
11249 */
11250 if (pg_index_form->indisreplident)
11251 {
11252 dirty = true;
11253 pg_index_form->indisreplident = false;
11254 }
11255 else if (thisIndexOid == indexOid)
11256 {
11257 dirty = true;
11258 pg_index_form->indisreplident = true;
11259 }
11260
11261 if (dirty)
11262 {
11263 simple_heap_update(pg_index, &pg_index_tuple->t_self, pg_index_tuple);
11264 CatalogUpdateIndexes(pg_index, pg_index_tuple);
11265 InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0,
11266 InvalidOid, is_internal);
11267 }
11268 heap_freetuple(pg_index_tuple);
11269 }
11270
11271 heap_close(pg_index, RowExclusiveLock);
11272 }
11273
11274 /*
11275 * ALTER TABLE <name> REPLICA IDENTITY ...
11276 */
11277 static void
ATExecReplicaIdentity(Relation rel,ReplicaIdentityStmt * stmt,LOCKMODE lockmode)11278 ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode)
11279 {
11280 Oid indexOid;
11281 Relation indexRel;
11282 int key;
11283
11284 if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT)
11285 {
11286 relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
11287 return;
11288 }
11289 else if (stmt->identity_type == REPLICA_IDENTITY_FULL)
11290 {
11291 relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
11292 return;
11293 }
11294 else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING)
11295 {
11296 relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
11297 return;
11298 }
11299 else if (stmt->identity_type == REPLICA_IDENTITY_INDEX)
11300 {
11301 /* fallthrough */ ;
11302 }
11303 else
11304 elog(ERROR, "unexpected identity type %u", stmt->identity_type);
11305
11306
11307 /* Check that the index exists */
11308 indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace);
11309 if (!OidIsValid(indexOid))
11310 ereport(ERROR,
11311 (errcode(ERRCODE_UNDEFINED_OBJECT),
11312 errmsg("index \"%s\" for table \"%s\" does not exist",
11313 stmt->name, RelationGetRelationName(rel))));
11314
11315 indexRel = index_open(indexOid, ShareLock);
11316
11317 /* Check that the index is on the relation we're altering. */
11318 if (indexRel->rd_index == NULL ||
11319 indexRel->rd_index->indrelid != RelationGetRelid(rel))
11320 ereport(ERROR,
11321 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
11322 errmsg("\"%s\" is not an index for table \"%s\"",
11323 RelationGetRelationName(indexRel),
11324 RelationGetRelationName(rel))));
11325 /* The AM must support uniqueness, and the index must in fact be unique. */
11326 if (!indexRel->rd_amroutine->amcanunique ||
11327 !indexRel->rd_index->indisunique)
11328 ereport(ERROR,
11329 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
11330 errmsg("cannot use non-unique index \"%s\" as replica identity",
11331 RelationGetRelationName(indexRel))));
11332 /* Deferred indexes are not guaranteed to be always unique. */
11333 if (!indexRel->rd_index->indimmediate)
11334 ereport(ERROR,
11335 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
11336 errmsg("cannot use non-immediate index \"%s\" as replica identity",
11337 RelationGetRelationName(indexRel))));
11338 /* Expression indexes aren't supported. */
11339 if (RelationGetIndexExpressions(indexRel) != NIL)
11340 ereport(ERROR,
11341 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
11342 errmsg("cannot use expression index \"%s\" as replica identity",
11343 RelationGetRelationName(indexRel))));
11344 /* Predicate indexes aren't supported. */
11345 if (RelationGetIndexPredicate(indexRel) != NIL)
11346 ereport(ERROR,
11347 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
11348 errmsg("cannot use partial index \"%s\" as replica identity",
11349 RelationGetRelationName(indexRel))));
11350 /* And neither are invalid indexes. */
11351 if (!IndexIsValid(indexRel->rd_index))
11352 ereport(ERROR,
11353 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
11354 errmsg("cannot use invalid index \"%s\" as replica identity",
11355 RelationGetRelationName(indexRel))));
11356
11357 /* Check index for nullable columns. */
11358 for (key = 0; key < indexRel->rd_index->indnatts; key++)
11359 {
11360 int16 attno = indexRel->rd_index->indkey.values[key];
11361 Form_pg_attribute attr;
11362
11363 /* Allow OID column to be indexed; it's certainly not nullable */
11364 if (attno == ObjectIdAttributeNumber)
11365 continue;
11366
11367 /*
11368 * Reject any other system columns. (Going forward, we'll disallow
11369 * indexes containing such columns in the first place, but they might
11370 * exist in older branches.)
11371 */
11372 if (attno <= 0)
11373 ereport(ERROR,
11374 (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
11375 errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column",
11376 RelationGetRelationName(indexRel), attno)));
11377
11378 attr = rel->rd_att->attrs[attno - 1];
11379 if (!attr->attnotnull)
11380 ereport(ERROR,
11381 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
11382 errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable",
11383 RelationGetRelationName(indexRel),
11384 NameStr(attr->attname))));
11385 }
11386
11387 /* This index is suitable for use as a replica identity. Mark it. */
11388 relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true);
11389
11390 index_close(indexRel, NoLock);
11391 }
11392
11393 /*
11394 * ALTER TABLE ENABLE/DISABLE ROW LEVEL SECURITY
11395 */
11396 static void
ATExecEnableRowSecurity(Relation rel)11397 ATExecEnableRowSecurity(Relation rel)
11398 {
11399 Relation pg_class;
11400 Oid relid;
11401 HeapTuple tuple;
11402
11403 relid = RelationGetRelid(rel);
11404
11405 pg_class = heap_open(RelationRelationId, RowExclusiveLock);
11406
11407 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
11408
11409 if (!HeapTupleIsValid(tuple))
11410 elog(ERROR, "cache lookup failed for relation %u", relid);
11411
11412 ((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = true;
11413 simple_heap_update(pg_class, &tuple->t_self, tuple);
11414
11415 /* keep catalog indexes current */
11416 CatalogUpdateIndexes(pg_class, tuple);
11417
11418 heap_close(pg_class, RowExclusiveLock);
11419 heap_freetuple(tuple);
11420 }
11421
11422 static void
ATExecDisableRowSecurity(Relation rel)11423 ATExecDisableRowSecurity(Relation rel)
11424 {
11425 Relation pg_class;
11426 Oid relid;
11427 HeapTuple tuple;
11428
11429 relid = RelationGetRelid(rel);
11430
11431 /* Pull the record for this relation and update it */
11432 pg_class = heap_open(RelationRelationId, RowExclusiveLock);
11433
11434 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
11435
11436 if (!HeapTupleIsValid(tuple))
11437 elog(ERROR, "cache lookup failed for relation %u", relid);
11438
11439 ((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = false;
11440 simple_heap_update(pg_class, &tuple->t_self, tuple);
11441
11442 /* keep catalog indexes current */
11443 CatalogUpdateIndexes(pg_class, tuple);
11444
11445 heap_close(pg_class, RowExclusiveLock);
11446 heap_freetuple(tuple);
11447 }
11448
11449 /*
11450 * ALTER TABLE FORCE/NO FORCE ROW LEVEL SECURITY
11451 */
11452 static void
ATExecForceNoForceRowSecurity(Relation rel,bool force_rls)11453 ATExecForceNoForceRowSecurity(Relation rel, bool force_rls)
11454 {
11455 Relation pg_class;
11456 Oid relid;
11457 HeapTuple tuple;
11458
11459 relid = RelationGetRelid(rel);
11460
11461 pg_class = heap_open(RelationRelationId, RowExclusiveLock);
11462
11463 tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
11464
11465 if (!HeapTupleIsValid(tuple))
11466 elog(ERROR, "cache lookup failed for relation %u", relid);
11467
11468 ((Form_pg_class) GETSTRUCT(tuple))->relforcerowsecurity = force_rls;
11469 simple_heap_update(pg_class, &tuple->t_self, tuple);
11470
11471 /* keep catalog indexes current */
11472 CatalogUpdateIndexes(pg_class, tuple);
11473
11474 heap_close(pg_class, RowExclusiveLock);
11475 heap_freetuple(tuple);
11476 }
11477
11478 /*
11479 * ALTER FOREIGN TABLE <name> OPTIONS (...)
11480 */
11481 static void
ATExecGenericOptions(Relation rel,List * options)11482 ATExecGenericOptions(Relation rel, List *options)
11483 {
11484 Relation ftrel;
11485 ForeignServer *server;
11486 ForeignDataWrapper *fdw;
11487 HeapTuple tuple;
11488 bool isnull;
11489 Datum repl_val[Natts_pg_foreign_table];
11490 bool repl_null[Natts_pg_foreign_table];
11491 bool repl_repl[Natts_pg_foreign_table];
11492 Datum datum;
11493 Form_pg_foreign_table tableform;
11494
11495 if (options == NIL)
11496 return;
11497
11498 ftrel = heap_open(ForeignTableRelationId, RowExclusiveLock);
11499
11500 tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, rel->rd_id);
11501 if (!HeapTupleIsValid(tuple))
11502 ereport(ERROR,
11503 (errcode(ERRCODE_UNDEFINED_OBJECT),
11504 errmsg("foreign table \"%s\" does not exist",
11505 RelationGetRelationName(rel))));
11506 tableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
11507 server = GetForeignServer(tableform->ftserver);
11508 fdw = GetForeignDataWrapper(server->fdwid);
11509
11510 memset(repl_val, 0, sizeof(repl_val));
11511 memset(repl_null, false, sizeof(repl_null));
11512 memset(repl_repl, false, sizeof(repl_repl));
11513
11514 /* Extract the current options */
11515 datum = SysCacheGetAttr(FOREIGNTABLEREL,
11516 tuple,
11517 Anum_pg_foreign_table_ftoptions,
11518 &isnull);
11519 if (isnull)
11520 datum = PointerGetDatum(NULL);
11521
11522 /* Transform the options */
11523 datum = transformGenericOptions(ForeignTableRelationId,
11524 datum,
11525 options,
11526 fdw->fdwvalidator);
11527
11528 if (PointerIsValid(DatumGetPointer(datum)))
11529 repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum;
11530 else
11531 repl_null[Anum_pg_foreign_table_ftoptions - 1] = true;
11532
11533 repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true;
11534
11535 /* Everything looks good - update the tuple */
11536
11537 tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel),
11538 repl_val, repl_null, repl_repl);
11539
11540 simple_heap_update(ftrel, &tuple->t_self, tuple);
11541 CatalogUpdateIndexes(ftrel, tuple);
11542
11543 /*
11544 * Invalidate relcache so that all sessions will refresh any cached plans
11545 * that might depend on the old options.
11546 */
11547 CacheInvalidateRelcache(rel);
11548
11549 InvokeObjectPostAlterHook(ForeignTableRelationId,
11550 RelationGetRelid(rel), 0);
11551
11552 heap_close(ftrel, RowExclusiveLock);
11553
11554 heap_freetuple(tuple);
11555 }
11556
11557 /*
11558 * Preparation phase for SET LOGGED/UNLOGGED
11559 *
11560 * This verifies that we're not trying to change a temp table. Also,
11561 * existing foreign key constraints are checked to avoid ending up with
11562 * permanent tables referencing unlogged tables.
11563 *
11564 * Return value is false if the operation is a no-op (in which case the
11565 * checks are skipped), otherwise true.
11566 */
11567 static bool
ATPrepChangePersistence(Relation rel,bool toLogged)11568 ATPrepChangePersistence(Relation rel, bool toLogged)
11569 {
11570 Relation pg_constraint;
11571 HeapTuple tuple;
11572 SysScanDesc scan;
11573 ScanKeyData skey[1];
11574
11575 /*
11576 * Disallow changing status for a temp table. Also verify whether we can
11577 * get away with doing nothing; in such cases we don't need to run the
11578 * checks below, either.
11579 */
11580 switch (rel->rd_rel->relpersistence)
11581 {
11582 case RELPERSISTENCE_TEMP:
11583 ereport(ERROR,
11584 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
11585 errmsg("cannot change logged status of table \"%s\" because it is temporary",
11586 RelationGetRelationName(rel)),
11587 errtable(rel)));
11588 break;
11589 case RELPERSISTENCE_PERMANENT:
11590 if (toLogged)
11591 /* nothing to do */
11592 return false;
11593 break;
11594 case RELPERSISTENCE_UNLOGGED:
11595 if (!toLogged)
11596 /* nothing to do */
11597 return false;
11598 break;
11599 }
11600
11601 /*
11602 * Check existing foreign key constraints to preserve the invariant that
11603 * permanent tables cannot reference unlogged ones. Self-referencing
11604 * foreign keys can safely be ignored.
11605 */
11606 pg_constraint = heap_open(ConstraintRelationId, AccessShareLock);
11607
11608 /*
11609 * Scan conrelid if changing to permanent, else confrelid. This also
11610 * determines whether a useful index exists.
11611 */
11612 ScanKeyInit(&skey[0],
11613 toLogged ? Anum_pg_constraint_conrelid :
11614 Anum_pg_constraint_confrelid,
11615 BTEqualStrategyNumber, F_OIDEQ,
11616 ObjectIdGetDatum(RelationGetRelid(rel)));
11617 scan = systable_beginscan(pg_constraint,
11618 toLogged ? ConstraintRelidIndexId : InvalidOid,
11619 true, NULL, 1, skey);
11620
11621 while (HeapTupleIsValid(tuple = systable_getnext(scan)))
11622 {
11623 Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple);
11624
11625 if (con->contype == CONSTRAINT_FOREIGN)
11626 {
11627 Oid foreignrelid;
11628 Relation foreignrel;
11629
11630 /* the opposite end of what we used as scankey */
11631 foreignrelid = toLogged ? con->confrelid : con->conrelid;
11632
11633 /* ignore if self-referencing */
11634 if (RelationGetRelid(rel) == foreignrelid)
11635 continue;
11636
11637 foreignrel = relation_open(foreignrelid, AccessShareLock);
11638
11639 if (toLogged)
11640 {
11641 if (foreignrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT)
11642 ereport(ERROR,
11643 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
11644 errmsg("could not change table \"%s\" to logged because it references unlogged table \"%s\"",
11645 RelationGetRelationName(rel),
11646 RelationGetRelationName(foreignrel)),
11647 errtableconstraint(rel, NameStr(con->conname))));
11648 }
11649 else
11650 {
11651 if (foreignrel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT)
11652 ereport(ERROR,
11653 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
11654 errmsg("could not change table \"%s\" to unlogged because it references logged table \"%s\"",
11655 RelationGetRelationName(rel),
11656 RelationGetRelationName(foreignrel)),
11657 errtableconstraint(rel, NameStr(con->conname))));
11658 }
11659
11660 relation_close(foreignrel, AccessShareLock);
11661 }
11662 }
11663
11664 systable_endscan(scan);
11665
11666 heap_close(pg_constraint, AccessShareLock);
11667
11668 return true;
11669 }
11670
11671 /*
11672 * Execute ALTER TABLE SET SCHEMA
11673 */
11674 ObjectAddress
AlterTableNamespace(AlterObjectSchemaStmt * stmt,Oid * oldschema)11675 AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema)
11676 {
11677 Relation rel;
11678 Oid relid;
11679 Oid oldNspOid;
11680 Oid nspOid;
11681 RangeVar *newrv;
11682 ObjectAddresses *objsMoved;
11683 ObjectAddress myself;
11684
11685 relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
11686 stmt->missing_ok, false,
11687 RangeVarCallbackForAlterRelation,
11688 (void *) stmt);
11689
11690 if (!OidIsValid(relid))
11691 {
11692 ereport(NOTICE,
11693 (errmsg("relation \"%s\" does not exist, skipping",
11694 stmt->relation->relname)));
11695 return InvalidObjectAddress;
11696 }
11697
11698 rel = relation_open(relid, NoLock);
11699
11700 oldNspOid = RelationGetNamespace(rel);
11701
11702 /* If it's an owned sequence, disallow moving it by itself. */
11703 if (rel->rd_rel->relkind == RELKIND_SEQUENCE)
11704 {
11705 Oid tableId;
11706 int32 colId;
11707
11708 if (sequenceIsOwned(relid, &tableId, &colId))
11709 ereport(ERROR,
11710 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
11711 errmsg("cannot move an owned sequence into another schema"),
11712 errdetail("Sequence \"%s\" is linked to table \"%s\".",
11713 RelationGetRelationName(rel),
11714 get_rel_name(tableId))));
11715 }
11716
11717 /* Get and lock schema OID and check its permissions. */
11718 newrv = makeRangeVar(stmt->newschema, RelationGetRelationName(rel), -1);
11719 nspOid = RangeVarGetAndCheckCreationNamespace(newrv, NoLock, NULL);
11720
11721 /* common checks on switching namespaces */
11722 CheckSetNamespace(oldNspOid, nspOid);
11723
11724 objsMoved = new_object_addresses();
11725 AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved);
11726 free_object_addresses(objsMoved);
11727
11728 ObjectAddressSet(myself, RelationRelationId, relid);
11729
11730 if (oldschema)
11731 *oldschema = oldNspOid;
11732
11733 /* close rel, but keep lock until commit */
11734 relation_close(rel, NoLock);
11735
11736 return myself;
11737 }
11738
11739 /*
11740 * The guts of relocating a table or materialized view to another namespace:
11741 * besides moving the relation itself, its dependent objects are relocated to
11742 * the new schema.
11743 */
11744 void
AlterTableNamespaceInternal(Relation rel,Oid oldNspOid,Oid nspOid,ObjectAddresses * objsMoved)11745 AlterTableNamespaceInternal(Relation rel, Oid oldNspOid, Oid nspOid,
11746 ObjectAddresses *objsMoved)
11747 {
11748 Relation classRel;
11749
11750 Assert(objsMoved != NULL);
11751
11752 /* OK, modify the pg_class row and pg_depend entry */
11753 classRel = heap_open(RelationRelationId, RowExclusiveLock);
11754
11755 AlterRelationNamespaceInternal(classRel, RelationGetRelid(rel), oldNspOid,
11756 nspOid, true, objsMoved);
11757
11758 /* Fix the table's row type too */
11759 AlterTypeNamespaceInternal(rel->rd_rel->reltype,
11760 nspOid, false, false, objsMoved);
11761
11762 /* Fix other dependent stuff */
11763 if (rel->rd_rel->relkind == RELKIND_RELATION ||
11764 rel->rd_rel->relkind == RELKIND_MATVIEW)
11765 {
11766 AlterIndexNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved);
11767 AlterSeqNamespaces(classRel, rel, oldNspOid, nspOid,
11768 objsMoved, AccessExclusiveLock);
11769 AlterConstraintNamespaces(RelationGetRelid(rel), oldNspOid, nspOid,
11770 false, objsMoved);
11771 }
11772
11773 heap_close(classRel, RowExclusiveLock);
11774 }
11775
11776 /*
11777 * The guts of relocating a relation to another namespace: fix the pg_class
11778 * entry, and the pg_depend entry if any. Caller must already have
11779 * opened and write-locked pg_class.
11780 */
11781 void
AlterRelationNamespaceInternal(Relation classRel,Oid relOid,Oid oldNspOid,Oid newNspOid,bool hasDependEntry,ObjectAddresses * objsMoved)11782 AlterRelationNamespaceInternal(Relation classRel, Oid relOid,
11783 Oid oldNspOid, Oid newNspOid,
11784 bool hasDependEntry,
11785 ObjectAddresses *objsMoved)
11786 {
11787 HeapTuple classTup;
11788 Form_pg_class classForm;
11789 ObjectAddress thisobj;
11790 bool already_done = false;
11791
11792 classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
11793 if (!HeapTupleIsValid(classTup))
11794 elog(ERROR, "cache lookup failed for relation %u", relOid);
11795 classForm = (Form_pg_class) GETSTRUCT(classTup);
11796
11797 Assert(classForm->relnamespace == oldNspOid);
11798
11799 thisobj.classId = RelationRelationId;
11800 thisobj.objectId = relOid;
11801 thisobj.objectSubId = 0;
11802
11803 /*
11804 * If the object has already been moved, don't move it again. If it's
11805 * already in the right place, don't move it, but still fire the object
11806 * access hook.
11807 */
11808 already_done = object_address_present(&thisobj, objsMoved);
11809 if (!already_done && oldNspOid != newNspOid)
11810 {
11811 /* check for duplicate name (more friendly than unique-index failure) */
11812 if (get_relname_relid(NameStr(classForm->relname),
11813 newNspOid) != InvalidOid)
11814 ereport(ERROR,
11815 (errcode(ERRCODE_DUPLICATE_TABLE),
11816 errmsg("relation \"%s\" already exists in schema \"%s\"",
11817 NameStr(classForm->relname),
11818 get_namespace_name(newNspOid))));
11819
11820 /* classTup is a copy, so OK to scribble on */
11821 classForm->relnamespace = newNspOid;
11822
11823 simple_heap_update(classRel, &classTup->t_self, classTup);
11824 CatalogUpdateIndexes(classRel, classTup);
11825
11826 /* Update dependency on schema if caller said so */
11827 if (hasDependEntry &&
11828 changeDependencyFor(RelationRelationId,
11829 relOid,
11830 NamespaceRelationId,
11831 oldNspOid,
11832 newNspOid) != 1)
11833 elog(ERROR, "failed to change schema dependency for relation \"%s\"",
11834 NameStr(classForm->relname));
11835 }
11836 if (!already_done)
11837 {
11838 add_exact_object_address(&thisobj, objsMoved);
11839
11840 InvokeObjectPostAlterHook(RelationRelationId, relOid, 0);
11841 }
11842
11843 heap_freetuple(classTup);
11844 }
11845
11846 /*
11847 * Move all indexes for the specified relation to another namespace.
11848 *
11849 * Note: we assume adequate permission checking was done by the caller,
11850 * and that the caller has a suitable lock on the owning relation.
11851 */
11852 static void
AlterIndexNamespaces(Relation classRel,Relation rel,Oid oldNspOid,Oid newNspOid,ObjectAddresses * objsMoved)11853 AlterIndexNamespaces(Relation classRel, Relation rel,
11854 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved)
11855 {
11856 List *indexList;
11857 ListCell *l;
11858
11859 indexList = RelationGetIndexList(rel);
11860
11861 foreach(l, indexList)
11862 {
11863 Oid indexOid = lfirst_oid(l);
11864 ObjectAddress thisobj;
11865
11866 thisobj.classId = RelationRelationId;
11867 thisobj.objectId = indexOid;
11868 thisobj.objectSubId = 0;
11869
11870 /*
11871 * Note: currently, the index will not have its own dependency on the
11872 * namespace, so we don't need to do changeDependencyFor(). There's no
11873 * row type in pg_type, either.
11874 *
11875 * XXX this objsMoved test may be pointless -- surely we have a single
11876 * dependency link from a relation to each index?
11877 */
11878 if (!object_address_present(&thisobj, objsMoved))
11879 {
11880 AlterRelationNamespaceInternal(classRel, indexOid,
11881 oldNspOid, newNspOid,
11882 false, objsMoved);
11883 add_exact_object_address(&thisobj, objsMoved);
11884 }
11885 }
11886
11887 list_free(indexList);
11888 }
11889
11890 /*
11891 * Move all SERIAL-column sequences of the specified relation to another
11892 * namespace.
11893 *
11894 * Note: we assume adequate permission checking was done by the caller,
11895 * and that the caller has a suitable lock on the owning relation.
11896 */
11897 static void
AlterSeqNamespaces(Relation classRel,Relation rel,Oid oldNspOid,Oid newNspOid,ObjectAddresses * objsMoved,LOCKMODE lockmode)11898 AlterSeqNamespaces(Relation classRel, Relation rel,
11899 Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
11900 LOCKMODE lockmode)
11901 {
11902 Relation depRel;
11903 SysScanDesc scan;
11904 ScanKeyData key[2];
11905 HeapTuple tup;
11906
11907 /*
11908 * SERIAL sequences are those having an auto dependency on one of the
11909 * table's columns (we don't care *which* column, exactly).
11910 */
11911 depRel = heap_open(DependRelationId, AccessShareLock);
11912
11913 ScanKeyInit(&key[0],
11914 Anum_pg_depend_refclassid,
11915 BTEqualStrategyNumber, F_OIDEQ,
11916 ObjectIdGetDatum(RelationRelationId));
11917 ScanKeyInit(&key[1],
11918 Anum_pg_depend_refobjid,
11919 BTEqualStrategyNumber, F_OIDEQ,
11920 ObjectIdGetDatum(RelationGetRelid(rel)));
11921 /* we leave refobjsubid unspecified */
11922
11923 scan = systable_beginscan(depRel, DependReferenceIndexId, true,
11924 NULL, 2, key);
11925
11926 while (HeapTupleIsValid(tup = systable_getnext(scan)))
11927 {
11928 Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
11929 Relation seqRel;
11930
11931 /* skip dependencies other than auto dependencies on columns */
11932 if (depForm->refobjsubid == 0 ||
11933 depForm->classid != RelationRelationId ||
11934 depForm->objsubid != 0 ||
11935 depForm->deptype != DEPENDENCY_AUTO)
11936 continue;
11937
11938 /* Use relation_open just in case it's an index */
11939 seqRel = relation_open(depForm->objid, lockmode);
11940
11941 /* skip non-sequence relations */
11942 if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
11943 {
11944 /* No need to keep the lock */
11945 relation_close(seqRel, lockmode);
11946 continue;
11947 }
11948
11949 /* Fix the pg_class and pg_depend entries */
11950 AlterRelationNamespaceInternal(classRel, depForm->objid,
11951 oldNspOid, newNspOid,
11952 true, objsMoved);
11953
11954 /*
11955 * Sequences have entries in pg_type. We need to be careful to move
11956 * them to the new namespace, too.
11957 */
11958 AlterTypeNamespaceInternal(RelationGetForm(seqRel)->reltype,
11959 newNspOid, false, false, objsMoved);
11960
11961 /* Now we can close it. Keep the lock till end of transaction. */
11962 relation_close(seqRel, NoLock);
11963 }
11964
11965 systable_endscan(scan);
11966
11967 relation_close(depRel, AccessShareLock);
11968 }
11969
11970
11971 /*
11972 * This code supports
11973 * CREATE TEMP TABLE ... ON COMMIT { DROP | PRESERVE ROWS | DELETE ROWS }
11974 *
11975 * Because we only support this for TEMP tables, it's sufficient to remember
11976 * the state in a backend-local data structure.
11977 */
11978
11979 /*
11980 * Register a newly-created relation's ON COMMIT action.
11981 */
11982 void
register_on_commit_action(Oid relid,OnCommitAction action)11983 register_on_commit_action(Oid relid, OnCommitAction action)
11984 {
11985 OnCommitItem *oc;
11986 MemoryContext oldcxt;
11987
11988 /*
11989 * We needn't bother registering the relation unless there is an ON COMMIT
11990 * action we need to take.
11991 */
11992 if (action == ONCOMMIT_NOOP || action == ONCOMMIT_PRESERVE_ROWS)
11993 return;
11994
11995 oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
11996
11997 oc = (OnCommitItem *) palloc(sizeof(OnCommitItem));
11998 oc->relid = relid;
11999 oc->oncommit = action;
12000 oc->creating_subid = GetCurrentSubTransactionId();
12001 oc->deleting_subid = InvalidSubTransactionId;
12002
12003 on_commits = lcons(oc, on_commits);
12004
12005 MemoryContextSwitchTo(oldcxt);
12006 }
12007
12008 /*
12009 * Unregister any ON COMMIT action when a relation is deleted.
12010 *
12011 * Actually, we only mark the OnCommitItem entry as to be deleted after commit.
12012 */
12013 void
remove_on_commit_action(Oid relid)12014 remove_on_commit_action(Oid relid)
12015 {
12016 ListCell *l;
12017
12018 foreach(l, on_commits)
12019 {
12020 OnCommitItem *oc = (OnCommitItem *) lfirst(l);
12021
12022 if (oc->relid == relid)
12023 {
12024 oc->deleting_subid = GetCurrentSubTransactionId();
12025 break;
12026 }
12027 }
12028 }
12029
12030 /*
12031 * Perform ON COMMIT actions.
12032 *
12033 * This is invoked just before actually committing, since it's possible
12034 * to encounter errors.
12035 */
12036 void
PreCommit_on_commit_actions(void)12037 PreCommit_on_commit_actions(void)
12038 {
12039 ListCell *l;
12040 List *oids_to_truncate = NIL;
12041
12042 foreach(l, on_commits)
12043 {
12044 OnCommitItem *oc = (OnCommitItem *) lfirst(l);
12045
12046 /* Ignore entry if already dropped in this xact */
12047 if (oc->deleting_subid != InvalidSubTransactionId)
12048 continue;
12049
12050 switch (oc->oncommit)
12051 {
12052 case ONCOMMIT_NOOP:
12053 case ONCOMMIT_PRESERVE_ROWS:
12054 /* Do nothing (there shouldn't be such entries, actually) */
12055 break;
12056 case ONCOMMIT_DELETE_ROWS:
12057
12058 /*
12059 * If this transaction hasn't accessed any temporary
12060 * relations, we can skip truncating ON COMMIT DELETE ROWS
12061 * tables, as they must still be empty.
12062 */
12063 if (MyXactAccessedTempRel)
12064 oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
12065 break;
12066 case ONCOMMIT_DROP:
12067 {
12068 ObjectAddress object;
12069
12070 object.classId = RelationRelationId;
12071 object.objectId = oc->relid;
12072 object.objectSubId = 0;
12073
12074 /*
12075 * Since this is an automatic drop, rather than one
12076 * directly initiated by the user, we pass the
12077 * PERFORM_DELETION_INTERNAL flag.
12078 */
12079 performDeletion(&object,
12080 DROP_CASCADE, PERFORM_DELETION_INTERNAL);
12081
12082 /*
12083 * Note that table deletion will call
12084 * remove_on_commit_action, so the entry should get marked
12085 * as deleted.
12086 */
12087 Assert(oc->deleting_subid != InvalidSubTransactionId);
12088 break;
12089 }
12090 }
12091 }
12092 if (oids_to_truncate != NIL)
12093 {
12094 heap_truncate(oids_to_truncate);
12095 CommandCounterIncrement(); /* XXX needed? */
12096 }
12097 }
12098
12099 /*
12100 * Post-commit or post-abort cleanup for ON COMMIT management.
12101 *
12102 * All we do here is remove no-longer-needed OnCommitItem entries.
12103 *
12104 * During commit, remove entries that were deleted during this transaction;
12105 * during abort, remove those created during this transaction.
12106 */
12107 void
AtEOXact_on_commit_actions(bool isCommit)12108 AtEOXact_on_commit_actions(bool isCommit)
12109 {
12110 ListCell *cur_item;
12111 ListCell *prev_item;
12112
12113 prev_item = NULL;
12114 cur_item = list_head(on_commits);
12115
12116 while (cur_item != NULL)
12117 {
12118 OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
12119
12120 if (isCommit ? oc->deleting_subid != InvalidSubTransactionId :
12121 oc->creating_subid != InvalidSubTransactionId)
12122 {
12123 /* cur_item must be removed */
12124 on_commits = list_delete_cell(on_commits, cur_item, prev_item);
12125 pfree(oc);
12126 if (prev_item)
12127 cur_item = lnext(prev_item);
12128 else
12129 cur_item = list_head(on_commits);
12130 }
12131 else
12132 {
12133 /* cur_item must be preserved */
12134 oc->creating_subid = InvalidSubTransactionId;
12135 oc->deleting_subid = InvalidSubTransactionId;
12136 prev_item = cur_item;
12137 cur_item = lnext(prev_item);
12138 }
12139 }
12140 }
12141
12142 /*
12143 * Post-subcommit or post-subabort cleanup for ON COMMIT management.
12144 *
12145 * During subabort, we can immediately remove entries created during this
12146 * subtransaction. During subcommit, just relabel entries marked during
12147 * this subtransaction as being the parent's responsibility.
12148 */
12149 void
AtEOSubXact_on_commit_actions(bool isCommit,SubTransactionId mySubid,SubTransactionId parentSubid)12150 AtEOSubXact_on_commit_actions(bool isCommit, SubTransactionId mySubid,
12151 SubTransactionId parentSubid)
12152 {
12153 ListCell *cur_item;
12154 ListCell *prev_item;
12155
12156 prev_item = NULL;
12157 cur_item = list_head(on_commits);
12158
12159 while (cur_item != NULL)
12160 {
12161 OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
12162
12163 if (!isCommit && oc->creating_subid == mySubid)
12164 {
12165 /* cur_item must be removed */
12166 on_commits = list_delete_cell(on_commits, cur_item, prev_item);
12167 pfree(oc);
12168 if (prev_item)
12169 cur_item = lnext(prev_item);
12170 else
12171 cur_item = list_head(on_commits);
12172 }
12173 else
12174 {
12175 /* cur_item must be preserved */
12176 if (oc->creating_subid == mySubid)
12177 oc->creating_subid = parentSubid;
12178 if (oc->deleting_subid == mySubid)
12179 oc->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
12180 prev_item = cur_item;
12181 cur_item = lnext(prev_item);
12182 }
12183 }
12184 }
12185
12186 /*
12187 * This is intended as a callback for RangeVarGetRelidExtended(). It allows
12188 * the relation to be locked only if (1) it's a plain table, materialized
12189 * view, or TOAST table and (2) the current user is the owner (or the
12190 * superuser). This meets the permission-checking needs of CLUSTER, REINDEX
12191 * TABLE, and REFRESH MATERIALIZED VIEW; we expose it here so that it can be
12192 * used by all.
12193 */
12194 void
RangeVarCallbackOwnsTable(const RangeVar * relation,Oid relId,Oid oldRelId,void * arg)12195 RangeVarCallbackOwnsTable(const RangeVar *relation,
12196 Oid relId, Oid oldRelId, void *arg)
12197 {
12198 char relkind;
12199
12200 /* Nothing to do if the relation was not found. */
12201 if (!OidIsValid(relId))
12202 return;
12203
12204 /*
12205 * If the relation does exist, check whether it's an index. But note that
12206 * the relation might have been dropped between the time we did the name
12207 * lookup and now. In that case, there's nothing to do.
12208 */
12209 relkind = get_rel_relkind(relId);
12210 if (!relkind)
12211 return;
12212 if (relkind != RELKIND_RELATION && relkind != RELKIND_TOASTVALUE &&
12213 relkind != RELKIND_MATVIEW)
12214 ereport(ERROR,
12215 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12216 errmsg("\"%s\" is not a table or materialized view", relation->relname)));
12217
12218 /* Check permissions */
12219 if (!pg_class_ownercheck(relId, GetUserId()))
12220 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, relation->relname);
12221 }
12222
12223 /*
12224 * Callback to RangeVarGetRelidExtended(), similar to
12225 * RangeVarCallbackOwnsTable() but without checks on the type of the relation.
12226 */
12227 void
RangeVarCallbackOwnsRelation(const RangeVar * relation,Oid relId,Oid oldRelId,void * arg)12228 RangeVarCallbackOwnsRelation(const RangeVar *relation,
12229 Oid relId, Oid oldRelId, void *arg)
12230 {
12231 HeapTuple tuple;
12232
12233 /* Nothing to do if the relation was not found. */
12234 if (!OidIsValid(relId))
12235 return;
12236
12237 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId));
12238 if (!HeapTupleIsValid(tuple)) /* should not happen */
12239 elog(ERROR, "cache lookup failed for relation %u", relId);
12240
12241 if (!pg_class_ownercheck(relId, GetUserId()))
12242 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
12243 relation->relname);
12244
12245 if (!allowSystemTableMods &&
12246 IsSystemClass(relId, (Form_pg_class) GETSTRUCT(tuple)))
12247 ereport(ERROR,
12248 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
12249 errmsg("permission denied: \"%s\" is a system catalog",
12250 relation->relname)));
12251
12252 ReleaseSysCache(tuple);
12253 }
12254
12255 /*
12256 * Common RangeVarGetRelid callback for rename, set schema, and alter table
12257 * processing.
12258 */
12259 static void
RangeVarCallbackForAlterRelation(const RangeVar * rv,Oid relid,Oid oldrelid,void * arg)12260 RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid,
12261 void *arg)
12262 {
12263 Node *stmt = (Node *) arg;
12264 ObjectType reltype;
12265 HeapTuple tuple;
12266 Form_pg_class classform;
12267 AclResult aclresult;
12268 char relkind;
12269
12270 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
12271 if (!HeapTupleIsValid(tuple))
12272 return; /* concurrently dropped */
12273 classform = (Form_pg_class) GETSTRUCT(tuple);
12274 relkind = classform->relkind;
12275
12276 /* Must own relation. */
12277 if (!pg_class_ownercheck(relid, GetUserId()))
12278 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, rv->relname);
12279
12280 /* No system table modifications unless explicitly allowed. */
12281 if (!allowSystemTableMods && IsSystemClass(relid, classform))
12282 ereport(ERROR,
12283 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
12284 errmsg("permission denied: \"%s\" is a system catalog",
12285 rv->relname)));
12286
12287 /*
12288 * Extract the specified relation type from the statement parse tree.
12289 *
12290 * Also, for ALTER .. RENAME, check permissions: the user must (still)
12291 * have CREATE rights on the containing namespace.
12292 */
12293 if (IsA(stmt, RenameStmt))
12294 {
12295 aclresult = pg_namespace_aclcheck(classform->relnamespace,
12296 GetUserId(), ACL_CREATE);
12297 if (aclresult != ACLCHECK_OK)
12298 aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
12299 get_namespace_name(classform->relnamespace));
12300 reltype = ((RenameStmt *) stmt)->renameType;
12301 }
12302 else if (IsA(stmt, AlterObjectSchemaStmt))
12303 reltype = ((AlterObjectSchemaStmt *) stmt)->objectType;
12304
12305 else if (IsA(stmt, AlterTableStmt))
12306 reltype = ((AlterTableStmt *) stmt)->relkind;
12307 else
12308 {
12309 reltype = OBJECT_TABLE; /* placate compiler */
12310 elog(ERROR, "unrecognized node type: %d", (int) nodeTag(stmt));
12311 }
12312
12313 /*
12314 * For compatibility with prior releases, we allow ALTER TABLE to be used
12315 * with most other types of relations (but not composite types). We allow
12316 * similar flexibility for ALTER INDEX in the case of RENAME, but not
12317 * otherwise. Otherwise, the user must select the correct form of the
12318 * command for the relation at issue.
12319 */
12320 if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE)
12321 ereport(ERROR,
12322 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12323 errmsg("\"%s\" is not a sequence", rv->relname)));
12324
12325 if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW)
12326 ereport(ERROR,
12327 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12328 errmsg("\"%s\" is not a view", rv->relname)));
12329
12330 if (reltype == OBJECT_MATVIEW && relkind != RELKIND_MATVIEW)
12331 ereport(ERROR,
12332 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12333 errmsg("\"%s\" is not a materialized view", rv->relname)));
12334
12335 if (reltype == OBJECT_FOREIGN_TABLE && relkind != RELKIND_FOREIGN_TABLE)
12336 ereport(ERROR,
12337 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12338 errmsg("\"%s\" is not a foreign table", rv->relname)));
12339
12340 if (reltype == OBJECT_TYPE && relkind != RELKIND_COMPOSITE_TYPE)
12341 ereport(ERROR,
12342 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12343 errmsg("\"%s\" is not a composite type", rv->relname)));
12344
12345 if (reltype == OBJECT_INDEX && relkind != RELKIND_INDEX
12346 && !IsA(stmt, RenameStmt))
12347 ereport(ERROR,
12348 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12349 errmsg("\"%s\" is not an index", rv->relname)));
12350
12351 /*
12352 * Don't allow ALTER TABLE on composite types. We want people to use ALTER
12353 * TYPE for that.
12354 */
12355 if (reltype != OBJECT_TYPE && relkind == RELKIND_COMPOSITE_TYPE)
12356 ereport(ERROR,
12357 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12358 errmsg("\"%s\" is a composite type", rv->relname),
12359 errhint("Use ALTER TYPE instead.")));
12360
12361 /*
12362 * Don't allow ALTER TABLE .. SET SCHEMA on relations that can't be moved
12363 * to a different schema, such as indexes and TOAST tables.
12364 */
12365 if (IsA(stmt, AlterObjectSchemaStmt) &&
12366 relkind != RELKIND_RELATION &&
12367 relkind != RELKIND_VIEW &&
12368 relkind != RELKIND_MATVIEW &&
12369 relkind != RELKIND_SEQUENCE &&
12370 relkind != RELKIND_FOREIGN_TABLE)
12371 ereport(ERROR,
12372 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
12373 errmsg("\"%s\" is not a table, view, materialized view, sequence, or foreign table",
12374 rv->relname)));
12375
12376 ReleaseSysCache(tuple);
12377 }
12378