prepare.h

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/*-------------------------------------------------------------------------
 *
 * prepare.h
 *    PREPARE, EXECUTE and DEALLOCATE commands, and prepared-stmt storage
 *
 *
 * Copyright (c) 2002-2024, PostgreSQL Global Development Group
 *
 * src/include/commands/prepare.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PREPARE_H
#define PREPARE_H
 
#include "commands/explain.h"
#include "datatype/timestamp.h"
#include "utils/plancache.h"
 
/*
 * The data structure representing a prepared statement.  This is now just
 * a thin veneer over a plancache entry --- the main addition is that of
 * a name.
 *
 * Note: all subsidiary storage lives in the referenced plancache entry.
 */
typedef struct
{
    /* dynahash.c requires key to be first field */
    char        stmt_name[NAMEDATALEN];
    CachedPlanSource *plansource;   /* the actual cached plan */
    bool        from_sql;       /* prepared via SQL, not FE/BE protocol? */
    TimestampTz prepare_time;   /* the time when the stmt was prepared */
} PreparedStatement;
 
 
/* Utility statements PREPARE, EXECUTE, DEALLOCATE, EXPLAIN EXECUTE */
extern void PrepareQuery(ParseState *pstate, PrepareStmt *stmt,
                         int stmt_location, int stmt_len);
extern void ExecuteQuery(ParseState *pstate,
                         ExecuteStmt *stmt, IntoClause *intoClause,
                         ParamListInfo params,
                         DestReceiver *dest, QueryCompletion *qc);
extern void DeallocateQuery(DeallocateStmt *stmt);
extern void ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into,
                                ExplainState *es, const char *queryString,
                                ParamListInfo params, QueryEnvironment *queryEnv);
 
/* Low-level access to stored prepared statements */
extern void StorePreparedStatement(const char *stmt_name,
                                   CachedPlanSource *plansource,
                                   bool from_sql);
extern PreparedStatement *FetchPreparedStatement(const char *stmt_name,
                                                 bool throwError);
extern void DropPreparedStatement(const char *stmt_name, bool showError);
extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
 
extern void DropAllPreparedStatements(void);
 
#endif                          /* PREPARE_H */