1 /*-------------------------------------------------------------------------
2  *
3  * prepare.h
4  *	  PREPARE, EXECUTE and DEALLOCATE commands, and prepared-stmt storage
5  *
6  *
7  * Copyright (c) 2002-2018, PostgreSQL Global Development Group
8  *
9  * src/include/commands/prepare.h
10  *
11  *-------------------------------------------------------------------------
12  */
13 #ifndef PREPARE_H
14 #define PREPARE_H
15 
16 #include "commands/explain.h"
17 #include "datatype/timestamp.h"
18 #include "utils/plancache.h"
19 
20 /*
21  * The data structure representing a prepared statement.  This is now just
22  * a thin veneer over a plancache entry --- the main addition is that of
23  * a name.
24  *
25  * Note: all subsidiary storage lives in the referenced plancache entry.
26  */
27 typedef struct
28 {
29 	/* dynahash.c requires key to be first field */
30 	char		stmt_name[NAMEDATALEN];
31 	CachedPlanSource *plansource;	/* the actual cached plan */
32 	bool		from_sql;		/* prepared via SQL, not FE/BE protocol? */
33 	TimestampTz prepare_time;	/* the time when the stmt was prepared */
34 } PreparedStatement;
35 
36 
37 /* Utility statements PREPARE, EXECUTE, DEALLOCATE, EXPLAIN EXECUTE */
38 extern void PrepareQuery(PrepareStmt *stmt, const char *queryString,
39 			 int stmt_location, int stmt_len);
40 extern void ExecuteQuery(ExecuteStmt *stmt, IntoClause *intoClause,
41 			 const char *queryString, ParamListInfo params,
42 			 DestReceiver *dest, char *completionTag);
43 extern void DeallocateQuery(DeallocateStmt *stmt);
44 extern void ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into,
45 					ExplainState *es, const char *queryString,
46 					ParamListInfo params, QueryEnvironment *queryEnv);
47 
48 /* Low-level access to stored prepared statements */
49 extern void StorePreparedStatement(const char *stmt_name,
50 					   CachedPlanSource *plansource,
51 					   bool from_sql);
52 extern PreparedStatement *FetchPreparedStatement(const char *stmt_name,
53 					   bool throwError);
54 extern void DropPreparedStatement(const char *stmt_name, bool showError);
55 extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
56 extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
57 
58 extern void DropAllPreparedStatements(void);
59 
60 #endif							/* PREPARE_H */
61