execdesc.h

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/*-------------------------------------------------------------------------
 *
 * execdesc.h
 *    plan and query descriptor accessor macros used by the executor
 *    and related modules.
 *
 *
 * Portions Copyright (c) 1996-2013, 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, or null if utility */
    Node       *utilitystmt;    /* utility statement, or null */
    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 */
    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 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,
                int instrument_options);

extern QueryDesc *CreateUtilityQueryDesc(Node *utilitystmt,
                       const char *sourceText,
                       Snapshot snapshot,
                       DestReceiver *dest,
                       ParamListInfo params);

extern void FreeQueryDesc(QueryDesc *qdesc);

#endif   /* EXECDESC_H  */