src/include/commands/prepare.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * prepare.h
   4  *        PREPARE, EXECUTE and DEALLOCATE commands, and prepared-stmt storage
   5  *
   6  *
   7  * Copyright (c) 2002-2009, PostgreSQL Global Development Group
   8  *
   9  * $PostgreSQL$
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef PREPARE_H
  14 #define PREPARE_H
  15
  16 #include "executor/executor.h"
  17 #include "utils/plancache.h"
  18 #include "utils/timestamp.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 extern void ExecuteQuery(ExecuteStmt *stmt, const char *queryString,
  40                          ParamListInfo params,
  41                          DestReceiver *dest, char *completionTag);
  42 extern void DeallocateQuery(DeallocateStmt *stmt);
  43 extern void ExplainExecuteQuery(ExecuteStmt *execstmt, ExplainStmt *stmt,
  44                                         const char *queryString,
  45                                         ParamListInfo params, TupOutputState *tstate);
  46
  47 /* Low-level access to stored prepared statements */
  48 extern void StorePreparedStatement(const char *stmt_name,
  49                                            Node *raw_parse_tree,
  50                                            const char *query_string,
  51                                            const char *commandTag,
  52                                            Oid *param_types,
  53                                            int num_params,
  54                                            int cursor_options,
  55                                            List *stmt_list,
  56                                            bool from_sql);
  57 extern PreparedStatement *FetchPreparedStatement(const char *stmt_name,
  58                                            bool throwError);
  59 extern void DropPreparedStatement(const char *stmt_name, bool showError);
  60 extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
  61 extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
  62
  63 void            DropAllPreparedStatements(void);
  64
  65 #endif   /* PREPARE_H */