execdesc.h

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/*-------------------------------------------------------------------------
 *
 * execdesc.h
 *    plan and query descriptor accessor macros used by the executor
 *    and related modules.
 *
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/executor/execdesc.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef EXECDESC_H
#define EXECDESC_H
 
#include "nodes/execnodes.h"
#include "tcop/dest.h"
 
 
/* ----------------
 *      query descriptor:
 *
 *  a QueryDesc encapsulates everything that the executor
 *  needs to execute the query.
 *
 *  For the convenience of SQL-language functions, we also support QueryDescs
 *  containing utility statements; these must not be passed to the executor
 *  however.
 * ---------------------
 */
typedef struct QueryDesc
{
    /* These fields are provided by CreateQueryDesc */
    CmdType     operation;      /* CMD_SELECT, CMD_UPDATE, etc. */
    PlannedStmt *plannedstmt;   /* planner's output (could be utility, too) */
    const char *sourceText;     /* source text of the query */
    Snapshot    snapshot;       /* snapshot to use for query */
    Snapshot    crosscheck_snapshot;    /* crosscheck for RI update/delete */
    DestReceiver *dest;         /* the destination for tuple output */
    ParamListInfo params;       /* param values being passed in */
    QueryEnvironment *queryEnv; /* query environment passed in */
    int         instrument_options; /* OR of InstrumentOption flags */
 
    /* These fields are set by ExecutorStart */
    TupleDesc   tupDesc;        /* descriptor for result tuples */
    EState     *estate;         /* executor's query-wide state */
    PlanState  *planstate;      /* tree of per-plan-node state */
 
    /* This field is set by ExecutorRun */
    bool        already_executed;   /* true if previously executed */
 
    /* This is always set NULL by the core system, but plugins can change it */
    struct Instrumentation *totaltime;  /* total time spent in ExecutorRun */
} QueryDesc;
 
/* in pquery.c */
extern QueryDesc *CreateQueryDesc(PlannedStmt *plannedstmt,
                                  const char *sourceText,
                                  Snapshot snapshot,
                                  Snapshot crosscheck_snapshot,
                                  DestReceiver *dest,
                                  ParamListInfo params,
                                  QueryEnvironment *queryEnv,
                                  int instrument_options);
 
extern void FreeQueryDesc(QueryDesc *qdesc);
 
#endif                          /* EXECDESC_H  */