1 /*------------------------------------------------------------------------- 2 * 3 * amapi.h 4 * API for Postgres index access methods. 5 * 6 * Copyright (c) 2015-2016, PostgreSQL Global Development Group 7 * 8 * src/include/access/amapi.h 9 * 10 *------------------------------------------------------------------------- 11 */ 12 #ifndef AMAPI_H 13 #define AMAPI_H 14 15 #include "access/genam.h" 16 17 /* 18 * We don't wish to include planner header files here, since most of an index 19 * AM's implementation isn't concerned with those data structures. To allow 20 * declaring amcostestimate_function here, use forward struct references. 21 */ 22 struct PlannerInfo; 23 struct IndexPath; 24 25 /* Likewise, this file shouldn't depend on execnodes.h. */ 26 struct IndexInfo; 27 28 29 /* 30 * Properties for amproperty API. This list covers properties known to the 31 * core code, but an index AM can define its own properties, by matching the 32 * string property name. 33 */ 34 typedef enum IndexAMProperty 35 { 36 AMPROP_UNKNOWN = 0, /* anything not known to core code */ 37 AMPROP_ASC, /* column properties */ 38 AMPROP_DESC, 39 AMPROP_NULLS_FIRST, 40 AMPROP_NULLS_LAST, 41 AMPROP_ORDERABLE, 42 AMPROP_DISTANCE_ORDERABLE, 43 AMPROP_RETURNABLE, 44 AMPROP_SEARCH_ARRAY, 45 AMPROP_SEARCH_NULLS, 46 AMPROP_CLUSTERABLE, /* index properties */ 47 AMPROP_INDEX_SCAN, 48 AMPROP_BITMAP_SCAN, 49 AMPROP_BACKWARD_SCAN, 50 AMPROP_CAN_ORDER, /* AM properties */ 51 AMPROP_CAN_UNIQUE, 52 AMPROP_CAN_MULTI_COL, 53 AMPROP_CAN_EXCLUDE 54 } IndexAMProperty; 55 56 57 /* 58 * Callback function signatures --- see indexam.sgml for more info. 59 */ 60 61 /* build new index */ 62 typedef IndexBuildResult *(*ambuild_function) (Relation heapRelation, 63 Relation indexRelation, 64 struct IndexInfo *indexInfo); 65 66 /* build empty index */ 67 typedef void (*ambuildempty_function) (Relation indexRelation); 68 69 /* insert this tuple */ 70 typedef bool (*aminsert_function) (Relation indexRelation, 71 Datum *values, 72 bool *isnull, 73 ItemPointer heap_tid, 74 Relation heapRelation, 75 IndexUniqueCheck checkUnique); 76 77 /* bulk delete */ 78 typedef IndexBulkDeleteResult *(*ambulkdelete_function) (IndexVacuumInfo *info, 79 IndexBulkDeleteResult *stats, 80 IndexBulkDeleteCallback callback, 81 void *callback_state); 82 83 /* post-VACUUM cleanup */ 84 typedef IndexBulkDeleteResult *(*amvacuumcleanup_function) (IndexVacuumInfo *info, 85 IndexBulkDeleteResult *stats); 86 87 /* can indexscan return IndexTuples? */ 88 typedef bool (*amcanreturn_function) (Relation indexRelation, int attno); 89 90 /* estimate cost of an indexscan */ 91 typedef void (*amcostestimate_function) (struct PlannerInfo *root, 92 struct IndexPath *path, 93 double loop_count, 94 Cost *indexStartupCost, 95 Cost *indexTotalCost, 96 Selectivity *indexSelectivity, 97 double *indexCorrelation); 98 99 /* parse index reloptions */ 100 typedef bytea *(*amoptions_function) (Datum reloptions, 101 bool validate); 102 103 /* report AM, index, or index column property */ 104 typedef bool (*amproperty_function) (Oid index_oid, int attno, 105 IndexAMProperty prop, const char *propname, 106 bool *res, bool *isnull); 107 108 /* validate definition of an opclass for this AM */ 109 typedef bool (*amvalidate_function) (Oid opclassoid); 110 111 /* prepare for index scan */ 112 typedef IndexScanDesc (*ambeginscan_function) (Relation indexRelation, 113 int nkeys, 114 int norderbys); 115 116 /* (re)start index scan */ 117 typedef void (*amrescan_function) (IndexScanDesc scan, 118 ScanKey keys, 119 int nkeys, 120 ScanKey orderbys, 121 int norderbys); 122 123 /* next valid tuple */ 124 typedef bool (*amgettuple_function) (IndexScanDesc scan, 125 ScanDirection direction); 126 127 /* fetch all valid tuples */ 128 typedef int64 (*amgetbitmap_function) (IndexScanDesc scan, 129 TIDBitmap *tbm); 130 131 /* end index scan */ 132 typedef void (*amendscan_function) (IndexScanDesc scan); 133 134 /* mark current scan position */ 135 typedef void (*ammarkpos_function) (IndexScanDesc scan); 136 137 /* restore marked scan position */ 138 typedef void (*amrestrpos_function) (IndexScanDesc scan); 139 140 141 /* 142 * API struct for an index AM. Note this must be stored in a single palloc'd 143 * chunk of memory. 144 */ 145 typedef struct IndexAmRoutine 146 { 147 NodeTag type; 148 149 /* 150 * Total number of strategies (operators) by which we can traverse/search 151 * this AM. Zero if AM does not have a fixed set of strategy assignments. 152 */ 153 uint16 amstrategies; 154 /* total number of support functions that this AM uses */ 155 uint16 amsupport; 156 /* does AM support ORDER BY indexed column's value? */ 157 bool amcanorder; 158 /* does AM support ORDER BY result of an operator on indexed column? */ 159 bool amcanorderbyop; 160 /* does AM support backward scanning? */ 161 bool amcanbackward; 162 /* does AM support UNIQUE indexes? */ 163 bool amcanunique; 164 /* does AM support multi-column indexes? */ 165 bool amcanmulticol; 166 /* does AM require scans to have a constraint on the first index column? */ 167 bool amoptionalkey; 168 /* does AM handle ScalarArrayOpExpr quals? */ 169 bool amsearcharray; 170 /* does AM handle IS NULL/IS NOT NULL quals? */ 171 bool amsearchnulls; 172 /* can index storage data type differ from column data type? */ 173 bool amstorage; 174 /* can an index of this type be clustered on? */ 175 bool amclusterable; 176 /* does AM handle predicate locks? */ 177 bool ampredlocks; 178 /* type of data stored in index, or InvalidOid if variable */ 179 Oid amkeytype; 180 181 /* interface functions */ 182 ambuild_function ambuild; 183 ambuildempty_function ambuildempty; 184 aminsert_function aminsert; 185 ambulkdelete_function ambulkdelete; 186 amvacuumcleanup_function amvacuumcleanup; 187 amcanreturn_function amcanreturn; /* can be NULL */ 188 amcostestimate_function amcostestimate; 189 amoptions_function amoptions; 190 amproperty_function amproperty; /* can be NULL */ 191 amvalidate_function amvalidate; 192 ambeginscan_function ambeginscan; 193 amrescan_function amrescan; 194 amgettuple_function amgettuple; /* can be NULL */ 195 amgetbitmap_function amgetbitmap; /* can be NULL */ 196 amendscan_function amendscan; 197 ammarkpos_function ammarkpos; /* can be NULL */ 198 amrestrpos_function amrestrpos; /* can be NULL */ 199 } IndexAmRoutine; 200 201 202 /* Functions in access/index/amapi.c */ 203 extern IndexAmRoutine *GetIndexAmRoutine(Oid amhandler); 204 extern IndexAmRoutine *GetIndexAmRoutineByAmId(Oid amoid, bool noerror); 205 206 extern Datum amvalidate(PG_FUNCTION_ARGS); 207 208 #endif /* AMAPI_H */ 209