At update of non-LP_NORMAL TID, fail instead of corrupting page header.

[pgsql.git] / src / backend / executor / execMain.c

/*-------------------------------------------------------------------------
 *
 * execMain.c
 *        top level executor interface routines
 *
 * INTERFACE ROUTINES
 *      ExecutorStart()
 *      ExecutorRun()
 *      ExecutorFinish()
 *      ExecutorEnd()
 *
 *      These four procedures are the external interface to the executor.
 *      In each case, the query descriptor is required as an argument.
 *
 *      ExecutorStart must be called at the beginning of execution of any
 *      query plan and ExecutorEnd must always be called at the end of
 *      execution of a plan (unless it is aborted due to error).
 *
 *      ExecutorRun accepts direction and count arguments that specify whether
 *      the plan is to be executed forwards, backwards, and for how many tuples.
 *      In some cases ExecutorRun may be called multiple times to process all
 *      the tuples for a plan.  It is also acceptable to stop short of executing
 *      the whole plan (but only if it is a SELECT).
 *
 *      ExecutorFinish must be called after the final ExecutorRun call and
 *      before ExecutorEnd.  This can be omitted only in case of EXPLAIN,
 *      which should also omit ExecutorRun.
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *        src/backend/executor/execMain.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/sysattr.h"
#include "access/table.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
#include "commands/matview.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/nodeSubplan.h"
#include "foreign/fdwapi.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/queryjumble.h"
#include "parser/parse_relation.h"
#include "pgstat.h"
#include "rewrite/rewriteHandler.h"
#include "tcop/utility.h"
#include "utils/acl.h"
#include "utils/backend_status.h"
#include "utils/lsyscache.h"
#include "utils/partcache.h"
#include "utils/rls.h"
#include "utils/snapmgr.h"


/* Hooks for plugins to get control in ExecutorStart/Run/Finish/End */
ExecutorStart_hook_type ExecutorStart_hook = NULL;
ExecutorRun_hook_type ExecutorRun_hook = NULL;
ExecutorFinish_hook_type ExecutorFinish_hook = NULL;
ExecutorEnd_hook_type ExecutorEnd_hook = NULL;

/* Hook for plugin to get control in ExecCheckPermissions() */
ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;

/* decls for local routines only used within this module */
static void InitPlan(QueryDesc *queryDesc, int eflags);
static void CheckValidRowMarkRel(Relation rel, RowMarkType markType);
static void ExecPostprocessPlan(EState *estate);
static void ExecEndPlan(PlanState *planstate, EState *estate);
static void ExecutePlan(QueryDesc *queryDesc,
                                                CmdType operation,
                                                bool sendTuples,
                                                uint64 numberTuples,
                                                ScanDirection direction,
                                                DestReceiver *dest);
static bool ExecCheckOneRelPerms(RTEPermissionInfo *perminfo);
static bool ExecCheckPermissionsModified(Oid relOid, Oid userid,
                                                                                 Bitmapset *modifiedCols,
                                                                                 AclMode requiredPerms);
static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
static void EvalPlanQualStart(EPQState *epqstate, Plan *planTree);

/* end of local decls */


/* ----------------------------------------------------------------
 *              ExecutorStart
 *
 *              This routine must be called at the beginning of any execution of any
 *              query plan
 *
 * Takes a QueryDesc previously created by CreateQueryDesc (which is separate
 * only because some places use QueryDescs for utility commands).  The tupDesc
 * field of the QueryDesc is filled in to describe the tuples that will be
 * returned, and the internal fields (estate and planstate) are set up.
 *
 * eflags contains flag bits as described in executor.h.
 *
 * NB: the CurrentMemoryContext when this is called will become the parent
 * of the per-query context used for this Executor invocation.
 *
 * We provide a function hook variable that lets loadable plugins
 * get control when ExecutorStart is called.  Such a plugin would
 * normally call standard_ExecutorStart().
 *
 * ----------------------------------------------------------------
 */
void
ExecutorStart(QueryDesc *queryDesc, int eflags)
{
        /*
         * In some cases (e.g. an EXECUTE statement or an execute message with the
         * extended query protocol) the query_id won't be reported, so do it now.
         *
         * Note that it's harmless to report the query_id multiple times, as the
         * call will be ignored if the top level query_id has already been
         * reported.
         */
        pgstat_report_query_id(queryDesc->plannedstmt->queryId, false);

        if (ExecutorStart_hook)
                (*ExecutorStart_hook) (queryDesc, eflags);
        else
                standard_ExecutorStart(queryDesc, eflags);
}

void
standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
{
        EState     *estate;
        MemoryContext oldcontext;

        /* sanity checks: queryDesc must not be started already */
        Assert(queryDesc != NULL);
        Assert(queryDesc->estate == NULL);

        /* caller must ensure the query's snapshot is active */
        Assert(GetActiveSnapshot() == queryDesc->snapshot);

        /*
         * If the transaction is read-only, we need to check if any writes are
         * planned to non-temporary tables.  EXPLAIN is considered read-only.
         *
         * Don't allow writes in parallel mode.  Supporting UPDATE and DELETE
         * would require (a) storing the combo CID hash in shared memory, rather
         * than synchronizing it just once at the start of parallelism, and (b) an
         * alternative to heap_update()'s reliance on xmax for mutual exclusion.
         * INSERT may have no such troubles, but we forbid it to simplify the
         * checks.
         *
         * We have lower-level defenses in CommandCounterIncrement and elsewhere
         * against performing unsafe operations in parallel mode, but this gives a
         * more user-friendly error message.
         */
        if ((XactReadOnly || IsInParallelMode()) &&
                !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
                ExecCheckXactReadOnly(queryDesc->plannedstmt);

        /*
         * Build EState, switch into per-query memory context for startup.
         */
        estate = CreateExecutorState();
        queryDesc->estate = estate;

        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        /*
         * Fill in external parameters, if any, from queryDesc; and allocate
         * workspace for internal parameters
         */
        estate->es_param_list_info = queryDesc->params;

        if (queryDesc->plannedstmt->paramExecTypes != NIL)
        {
                int                     nParamExec;

                nParamExec = list_length(queryDesc->plannedstmt->paramExecTypes);
                estate->es_param_exec_vals = (ParamExecData *)
                        palloc0(nParamExec * sizeof(ParamExecData));
        }

        /* We now require all callers to provide sourceText */
        Assert(queryDesc->sourceText != NULL);
        estate->es_sourceText = queryDesc->sourceText;

        /*
         * Fill in the query environment, if any, from queryDesc.
         */
        estate->es_queryEnv = queryDesc->queryEnv;

        /*
         * If non-read-only query, set the command ID to mark output tuples with
         */
        switch (queryDesc->operation)
        {
                case CMD_SELECT:

                        /*
                         * SELECT FOR [KEY] UPDATE/SHARE and modifying CTEs need to mark
                         * tuples
                         */
                        if (queryDesc->plannedstmt->rowMarks != NIL ||
                                queryDesc->plannedstmt->hasModifyingCTE)
                                estate->es_output_cid = GetCurrentCommandId(true);

                        /*
                         * A SELECT without modifying CTEs can't possibly queue triggers,
                         * so force skip-triggers mode. This is just a marginal efficiency
                         * hack, since AfterTriggerBeginQuery/AfterTriggerEndQuery aren't
                         * all that expensive, but we might as well do it.
                         */
                        if (!queryDesc->plannedstmt->hasModifyingCTE)
                                eflags |= EXEC_FLAG_SKIP_TRIGGERS;
                        break;

                case CMD_INSERT:
                case CMD_DELETE:
                case CMD_UPDATE:
                case CMD_MERGE:
                        estate->es_output_cid = GetCurrentCommandId(true);
                        break;

                default:
                        elog(ERROR, "unrecognized operation code: %d",
                                 (int) queryDesc->operation);
                        break;
        }

        /*
         * Copy other important information into the EState
         */
        estate->es_snapshot = RegisterSnapshot(queryDesc->snapshot);
        estate->es_crosscheck_snapshot = RegisterSnapshot(queryDesc->crosscheck_snapshot);
        estate->es_top_eflags = eflags;
        estate->es_instrument = queryDesc->instrument_options;
        estate->es_jit_flags = queryDesc->plannedstmt->jitFlags;

        /*
         * Set up an AFTER-trigger statement context, unless told not to, or
         * unless it's EXPLAIN-only mode (when ExecutorFinish won't be called).
         */
        if (!(eflags & (EXEC_FLAG_SKIP_TRIGGERS | EXEC_FLAG_EXPLAIN_ONLY)))
                AfterTriggerBeginQuery();

        /*
         * Initialize the plan state tree
         */
        InitPlan(queryDesc, eflags);

        MemoryContextSwitchTo(oldcontext);
}

/* ----------------------------------------------------------------
 *              ExecutorRun
 *
 *              This is the main routine of the executor module. It accepts
 *              the query descriptor from the traffic cop and executes the
 *              query plan.
 *
 *              ExecutorStart must have been called already.
 *
 *              If direction is NoMovementScanDirection then nothing is done
 *              except to start up/shut down the destination.  Otherwise,
 *              we retrieve up to 'count' tuples in the specified direction.
 *
 *              Note: count = 0 is interpreted as no portal limit, i.e., run to
 *              completion.  Also note that the count limit is only applied to
 *              retrieved tuples, not for instance to those inserted/updated/deleted
 *              by a ModifyTable plan node.
 *
 *              There is no return value, but output tuples (if any) are sent to
 *              the destination receiver specified in the QueryDesc; and the number
 *              of tuples processed at the top level can be found in
 *              estate->es_processed.  The total number of tuples processed in all
 *              the ExecutorRun calls can be found in estate->es_total_processed.
 *
 *              We provide a function hook variable that lets loadable plugins
 *              get control when ExecutorRun is called.  Such a plugin would
 *              normally call standard_ExecutorRun().
 *
 * ----------------------------------------------------------------
 */
void
ExecutorRun(QueryDesc *queryDesc,
                        ScanDirection direction, uint64 count)
{
        if (ExecutorRun_hook)
                (*ExecutorRun_hook) (queryDesc, direction, count);
        else
                standard_ExecutorRun(queryDesc, direction, count);
}

void
standard_ExecutorRun(QueryDesc *queryDesc,
                                         ScanDirection direction, uint64 count)
{
        EState     *estate;
        CmdType         operation;
        DestReceiver *dest;
        bool            sendTuples;
        MemoryContext oldcontext;

        /* sanity checks */
        Assert(queryDesc != NULL);

        estate = queryDesc->estate;

        Assert(estate != NULL);
        Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));

        /* caller must ensure the query's snapshot is active */
        Assert(GetActiveSnapshot() == estate->es_snapshot);

        /*
         * Switch into per-query memory context
         */
        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        /* Allow instrumentation of Executor overall runtime */
        if (queryDesc->totaltime)
                InstrStartNode(queryDesc->totaltime);

        /*
         * extract information from the query descriptor and the query feature.
         */
        operation = queryDesc->operation;
        dest = queryDesc->dest;

        /*
         * startup tuple receiver, if we will be emitting tuples
         */
        estate->es_processed = 0;

        sendTuples = (operation == CMD_SELECT ||
                                  queryDesc->plannedstmt->hasReturning);

        if (sendTuples)
                dest->rStartup(dest, operation, queryDesc->tupDesc);

        /*
         * Run plan, unless direction is NoMovement.
         *
         * Note: pquery.c selects NoMovement if a prior call already reached
         * end-of-data in the user-specified fetch direction.  This is important
         * because various parts of the executor can misbehave if called again
         * after reporting EOF.  For example, heapam.c would actually restart a
         * heapscan and return all its data afresh.  There is also some doubt
         * about whether a parallel plan would operate properly if an additional,
         * necessarily non-parallel execution request occurs after completing a
         * parallel execution.  (That case should work, but it's untested.)
         */
        if (!ScanDirectionIsNoMovement(direction))
                ExecutePlan(queryDesc,
                                        operation,
                                        sendTuples,
                                        count,
                                        direction,
                                        dest);

        /*
         * Update es_total_processed to keep track of the number of tuples
         * processed across multiple ExecutorRun() calls.
         */
        estate->es_total_processed += estate->es_processed;

        /*
         * shutdown tuple receiver, if we started it
         */
        if (sendTuples)
                dest->rShutdown(dest);

        if (queryDesc->totaltime)
                InstrStopNode(queryDesc->totaltime, estate->es_processed);

        MemoryContextSwitchTo(oldcontext);
}

/* ----------------------------------------------------------------
 *              ExecutorFinish
 *
 *              This routine must be called after the last ExecutorRun call.
 *              It performs cleanup such as firing AFTER triggers.  It is
 *              separate from ExecutorEnd because EXPLAIN ANALYZE needs to
 *              include these actions in the total runtime.
 *
 *              We provide a function hook variable that lets loadable plugins
 *              get control when ExecutorFinish is called.  Such a plugin would
 *              normally call standard_ExecutorFinish().
 *
 * ----------------------------------------------------------------
 */
void
ExecutorFinish(QueryDesc *queryDesc)
{
        if (ExecutorFinish_hook)
                (*ExecutorFinish_hook) (queryDesc);
        else
                standard_ExecutorFinish(queryDesc);
}

void
standard_ExecutorFinish(QueryDesc *queryDesc)
{
        EState     *estate;
        MemoryContext oldcontext;

        /* sanity checks */
        Assert(queryDesc != NULL);

        estate = queryDesc->estate;

        Assert(estate != NULL);
        Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));

        /* This should be run once and only once per Executor instance */
        Assert(!estate->es_finished);

        /* Switch into per-query memory context */
        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        /* Allow instrumentation of Executor overall runtime */
        if (queryDesc->totaltime)
                InstrStartNode(queryDesc->totaltime);

        /* Run ModifyTable nodes to completion */
        ExecPostprocessPlan(estate);

        /* Execute queued AFTER triggers, unless told not to */
        if (!(estate->es_top_eflags & EXEC_FLAG_SKIP_TRIGGERS))
                AfterTriggerEndQuery(estate);

        if (queryDesc->totaltime)
                InstrStopNode(queryDesc->totaltime, 0);

        MemoryContextSwitchTo(oldcontext);

        estate->es_finished = true;
}

/* ----------------------------------------------------------------
 *              ExecutorEnd
 *
 *              This routine must be called at the end of execution of any
 *              query plan
 *
 *              We provide a function hook variable that lets loadable plugins
 *              get control when ExecutorEnd is called.  Such a plugin would
 *              normally call standard_ExecutorEnd().
 *
 * ----------------------------------------------------------------
 */
void
ExecutorEnd(QueryDesc *queryDesc)
{
        if (ExecutorEnd_hook)
                (*ExecutorEnd_hook) (queryDesc);
        else
                standard_ExecutorEnd(queryDesc);
}

void
standard_ExecutorEnd(QueryDesc *queryDesc)
{
        EState     *estate;
        MemoryContext oldcontext;

        /* sanity checks */
        Assert(queryDesc != NULL);

        estate = queryDesc->estate;

        Assert(estate != NULL);

        if (estate->es_parallel_workers_to_launch > 0)
                pgstat_update_parallel_workers_stats((PgStat_Counter) estate->es_parallel_workers_to_launch,
                                                                                         (PgStat_Counter) estate->es_parallel_workers_launched);

        /*
         * Check that ExecutorFinish was called, unless in EXPLAIN-only mode. This
         * Assert is needed because ExecutorFinish is new as of 9.1, and callers
         * might forget to call it.
         */
        Assert(estate->es_finished ||
                   (estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));

        /*
         * Switch into per-query memory context to run ExecEndPlan
         */
        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        ExecEndPlan(queryDesc->planstate, estate);

        /* do away with our snapshots */
        UnregisterSnapshot(estate->es_snapshot);
        UnregisterSnapshot(estate->es_crosscheck_snapshot);

        /*
         * Must switch out of context before destroying it
         */
        MemoryContextSwitchTo(oldcontext);

        /*
         * Release EState and per-query memory context.  This should release
         * everything the executor has allocated.
         */
        FreeExecutorState(estate);

        /* Reset queryDesc fields that no longer point to anything */
        queryDesc->tupDesc = NULL;
        queryDesc->estate = NULL;
        queryDesc->planstate = NULL;
        queryDesc->totaltime = NULL;
}

/* ----------------------------------------------------------------
 *              ExecutorRewind
 *
 *              This routine may be called on an open queryDesc to rewind it
 *              to the start.
 * ----------------------------------------------------------------
 */
void
ExecutorRewind(QueryDesc *queryDesc)
{
        EState     *estate;
        MemoryContext oldcontext;

        /* sanity checks */
        Assert(queryDesc != NULL);

        estate = queryDesc->estate;

        Assert(estate != NULL);

        /* It's probably not sensible to rescan updating queries */
        Assert(queryDesc->operation == CMD_SELECT);

        /*
         * Switch into per-query memory context
         */
        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        /*
         * rescan plan
         */
        ExecReScan(queryDesc->planstate);

        MemoryContextSwitchTo(oldcontext);
}


/*
 * ExecCheckPermissions
 *              Check access permissions of relations mentioned in a query
 *
 * Returns true if permissions are adequate.  Otherwise, throws an appropriate
 * error if ereport_on_violation is true, or simply returns false otherwise.
 *
 * Note that this does NOT address row-level security policies (aka: RLS).  If
 * rows will be returned to the user as a result of this permission check
 * passing, then RLS also needs to be consulted (and check_enable_rls()).
 *
 * See rewrite/rowsecurity.c.
 *
 * NB: rangeTable is no longer used by us, but kept around for the hooks that
 * might still want to look at the RTEs.
 */
bool
ExecCheckPermissions(List *rangeTable, List *rteperminfos,
                                         bool ereport_on_violation)
{
        ListCell   *l;
        bool            result = true;

#ifdef USE_ASSERT_CHECKING
        Bitmapset  *indexset = NULL;

        /* Check that rteperminfos is consistent with rangeTable */
        foreach(l, rangeTable)
        {
                RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);

                if (rte->perminfoindex != 0)
                {
                        /* Sanity checks */

                        /*
                         * Only relation RTEs and subquery RTEs that were once relation
                         * RTEs (views) have their perminfoindex set.
                         */
                        Assert(rte->rtekind == RTE_RELATION ||
                                   (rte->rtekind == RTE_SUBQUERY &&
                                        rte->relkind == RELKIND_VIEW));

                        (void) getRTEPermissionInfo(rteperminfos, rte);
                        /* Many-to-one mapping not allowed */
                        Assert(!bms_is_member(rte->perminfoindex, indexset));
                        indexset = bms_add_member(indexset, rte->perminfoindex);
                }
        }

        /* All rteperminfos are referenced */
        Assert(bms_num_members(indexset) == list_length(rteperminfos));
#endif

        foreach(l, rteperminfos)
        {
                RTEPermissionInfo *perminfo = lfirst_node(RTEPermissionInfo, l);

                Assert(OidIsValid(perminfo->relid));
                result = ExecCheckOneRelPerms(perminfo);
                if (!result)
                {
                        if (ereport_on_violation)
                                aclcheck_error(ACLCHECK_NO_PRIV,
                                                           get_relkind_objtype(get_rel_relkind(perminfo->relid)),
                                                           get_rel_name(perminfo->relid));
                        return false;
                }
        }

        if (ExecutorCheckPerms_hook)
                result = (*ExecutorCheckPerms_hook) (rangeTable, rteperminfos,
                                                                                         ereport_on_violation);
        return result;
}

/*
 * ExecCheckOneRelPerms
 *              Check access permissions for a single relation.
 */
static bool
ExecCheckOneRelPerms(RTEPermissionInfo *perminfo)
{
        AclMode         requiredPerms;
        AclMode         relPerms;
        AclMode         remainingPerms;
        Oid                     userid;
        Oid                     relOid = perminfo->relid;

        requiredPerms = perminfo->requiredPerms;
        Assert(requiredPerms != 0);

        /*
         * userid to check as: current user unless we have a setuid indication.
         *
         * Note: GetUserId() is presently fast enough that there's no harm in
         * calling it separately for each relation.  If that stops being true, we
         * could call it once in ExecCheckPermissions and pass the userid down
         * from there.  But for now, no need for the extra clutter.
         */
        userid = OidIsValid(perminfo->checkAsUser) ?
                perminfo->checkAsUser : GetUserId();

        /*
         * We must have *all* the requiredPerms bits, but some of the bits can be
         * satisfied from column-level rather than relation-level permissions.
         * First, remove any bits that are satisfied by relation permissions.
         */
        relPerms = pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL);
        remainingPerms = requiredPerms & ~relPerms;
        if (remainingPerms != 0)
        {
                int                     col = -1;

                /*
                 * If we lack any permissions that exist only as relation permissions,
                 * we can fail straight away.
                 */
                if (remainingPerms & ~(ACL_SELECT | ACL_INSERT | ACL_UPDATE))
                        return false;

                /*
                 * Check to see if we have the needed privileges at column level.
                 *
                 * Note: failures just report a table-level error; it would be nicer
                 * to report a column-level error if we have some but not all of the
                 * column privileges.
                 */
                if (remainingPerms & ACL_SELECT)
                {
                        /*
                         * When the query doesn't explicitly reference any columns (for
                         * example, SELECT COUNT(*) FROM table), allow the query if we
                         * have SELECT on any column of the rel, as per SQL spec.
                         */
                        if (bms_is_empty(perminfo->selectedCols))
                        {
                                if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
                                                                                          ACLMASK_ANY) != ACLCHECK_OK)
                                        return false;
                        }

                        while ((col = bms_next_member(perminfo->selectedCols, col)) >= 0)
                        {
                                /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
                                AttrNumber      attno = col + FirstLowInvalidHeapAttributeNumber;

                                if (attno == InvalidAttrNumber)
                                {
                                        /* Whole-row reference, must have priv on all cols */
                                        if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
                                                                                                  ACLMASK_ALL) != ACLCHECK_OK)
                                                return false;
                                }
                                else
                                {
                                        if (pg_attribute_aclcheck(relOid, attno, userid,
                                                                                          ACL_SELECT) != ACLCHECK_OK)
                                                return false;
                                }
                        }
                }

                /*
                 * Basically the same for the mod columns, for both INSERT and UPDATE
                 * privilege as specified by remainingPerms.
                 */
                if (remainingPerms & ACL_INSERT &&
                        !ExecCheckPermissionsModified(relOid,
                                                                                  userid,
                                                                                  perminfo->insertedCols,
                                                                                  ACL_INSERT))
                        return false;

                if (remainingPerms & ACL_UPDATE &&
                        !ExecCheckPermissionsModified(relOid,
                                                                                  userid,
                                                                                  perminfo->updatedCols,
                                                                                  ACL_UPDATE))
                        return false;
        }
        return true;
}

/*
 * ExecCheckPermissionsModified
 *              Check INSERT or UPDATE access permissions for a single relation (these
 *              are processed uniformly).
 */
static bool
ExecCheckPermissionsModified(Oid relOid, Oid userid, Bitmapset *modifiedCols,
                                                         AclMode requiredPerms)
{
        int                     col = -1;

        /*
         * When the query doesn't explicitly update any columns, allow the query
         * if we have permission on any column of the rel.  This is to handle
         * SELECT FOR UPDATE as well as possible corner cases in UPDATE.
         */
        if (bms_is_empty(modifiedCols))
        {
                if (pg_attribute_aclcheck_all(relOid, userid, requiredPerms,
                                                                          ACLMASK_ANY) != ACLCHECK_OK)
                        return false;
        }

        while ((col = bms_next_member(modifiedCols, col)) >= 0)
        {
                /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
                AttrNumber      attno = col + FirstLowInvalidHeapAttributeNumber;

                if (attno == InvalidAttrNumber)
                {
                        /* whole-row reference can't happen here */
                        elog(ERROR, "whole-row update is not implemented");
                }
                else
                {
                        if (pg_attribute_aclcheck(relOid, attno, userid,
                                                                          requiredPerms) != ACLCHECK_OK)
                                return false;
                }
        }
        return true;
}

/*
 * Check that the query does not imply any writes to non-temp tables;
 * unless we're in parallel mode, in which case don't even allow writes
 * to temp tables.
 *
 * Note: in a Hot Standby this would need to reject writes to temp
 * tables just as we do in parallel mode; but an HS standby can't have created
 * any temp tables in the first place, so no need to check that.
 */
static void
ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
{
        ListCell   *l;

        /*
         * Fail if write permissions are requested in parallel mode for table
         * (temp or non-temp), otherwise fail for any non-temp table.
         */
        foreach(l, plannedstmt->permInfos)
        {
                RTEPermissionInfo *perminfo = lfirst_node(RTEPermissionInfo, l);

                if ((perminfo->requiredPerms & (~ACL_SELECT)) == 0)
                        continue;

                if (isTempNamespace(get_rel_namespace(perminfo->relid)))
                        continue;

                PreventCommandIfReadOnly(CreateCommandName((Node *) plannedstmt));
        }

        if (plannedstmt->commandType != CMD_SELECT || plannedstmt->hasModifyingCTE)
                PreventCommandIfParallelMode(CreateCommandName((Node *) plannedstmt));
}


/* ----------------------------------------------------------------
 *              InitPlan
 *
 *              Initializes the query plan: open files, allocate storage
 *              and start up the rule manager
 * ----------------------------------------------------------------
 */
static void
InitPlan(QueryDesc *queryDesc, int eflags)
{
        CmdType         operation = queryDesc->operation;
        PlannedStmt *plannedstmt = queryDesc->plannedstmt;
        Plan       *plan = plannedstmt->planTree;
        List       *rangeTable = plannedstmt->rtable;
        EState     *estate = queryDesc->estate;
        PlanState  *planstate;
        TupleDesc       tupType;
        ListCell   *l;
        int                     i;

        /*
         * Do permissions checks
         */
        ExecCheckPermissions(rangeTable, plannedstmt->permInfos, true);

        /*
         * initialize the node's execution state
         */
        ExecInitRangeTable(estate, rangeTable, plannedstmt->permInfos);

        estate->es_plannedstmt = plannedstmt;

        /*
         * Next, build the ExecRowMark array from the PlanRowMark(s), if any.
         */
        if (plannedstmt->rowMarks)
        {
                estate->es_rowmarks = (ExecRowMark **)
                        palloc0(estate->es_range_table_size * sizeof(ExecRowMark *));
                foreach(l, plannedstmt->rowMarks)
                {
                        PlanRowMark *rc = (PlanRowMark *) lfirst(l);
                        Oid                     relid;
                        Relation        relation;
                        ExecRowMark *erm;

                        /* ignore "parent" rowmarks; they are irrelevant at runtime */
                        if (rc->isParent)
                                continue;

                        /* get relation's OID (will produce InvalidOid if subquery) */
                        relid = exec_rt_fetch(rc->rti, estate)->relid;

                        /* open relation, if we need to access it for this mark type */
                        switch (rc->markType)
                        {
                                case ROW_MARK_EXCLUSIVE:
                                case ROW_MARK_NOKEYEXCLUSIVE:
                                case ROW_MARK_SHARE:
                                case ROW_MARK_KEYSHARE:
                                case ROW_MARK_REFERENCE:
                                        relation = ExecGetRangeTableRelation(estate, rc->rti);
                                        break;
                                case ROW_MARK_COPY:
                                        /* no physical table access is required */
                                        relation = NULL;
                                        break;
                                default:
                                        elog(ERROR, "unrecognized markType: %d", rc->markType);
                                        relation = NULL;        /* keep compiler quiet */
                                        break;
                        }

                        /* Check that relation is a legal target for marking */
                        if (relation)
                                CheckValidRowMarkRel(relation, rc->markType);

                        erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
                        erm->relation = relation;
                        erm->relid = relid;
                        erm->rti = rc->rti;
                        erm->prti = rc->prti;
                        erm->rowmarkId = rc->rowmarkId;
                        erm->markType = rc->markType;
                        erm->strength = rc->strength;
                        erm->waitPolicy = rc->waitPolicy;
                        erm->ermActive = false;
                        ItemPointerSetInvalid(&(erm->curCtid));
                        erm->ermExtra = NULL;

                        Assert(erm->rti > 0 && erm->rti <= estate->es_range_table_size &&
                                   estate->es_rowmarks[erm->rti - 1] == NULL);

                        estate->es_rowmarks[erm->rti - 1] = erm;
                }
        }

        /*
         * Initialize the executor's tuple table to empty.
         */
        estate->es_tupleTable = NIL;

        /* signal that this EState is not used for EPQ */
        estate->es_epq_active = NULL;

        /*
         * Initialize private state information for each SubPlan.  We must do this
         * before running ExecInitNode on the main query tree, since
         * ExecInitSubPlan expects to be able to find these entries.
         */
        Assert(estate->es_subplanstates == NIL);
        i = 1;                                          /* subplan indices count from 1 */
        foreach(l, plannedstmt->subplans)
        {
                Plan       *subplan = (Plan *) lfirst(l);
                PlanState  *subplanstate;
                int                     sp_eflags;

                /*
                 * A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
                 * it is a parameterless subplan (not initplan), we suggest that it be
                 * prepared to handle REWIND efficiently; otherwise there is no need.
                 */
                sp_eflags = eflags
                        & ~(EXEC_FLAG_REWIND | EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK);
                if (bms_is_member(i, plannedstmt->rewindPlanIDs))
                        sp_eflags |= EXEC_FLAG_REWIND;

                subplanstate = ExecInitNode(subplan, estate, sp_eflags);

                estate->es_subplanstates = lappend(estate->es_subplanstates,
                                                                                   subplanstate);

                i++;
        }

        /*
         * Initialize the private state information for all the nodes in the query
         * tree.  This opens files, allocates storage and leaves us ready to start
         * processing tuples.
         */
        planstate = ExecInitNode(plan, estate, eflags);

        /*
         * Get the tuple descriptor describing the type of tuples to return.
         */
        tupType = ExecGetResultType(planstate);

        /*
         * Initialize the junk filter if needed.  SELECT queries need a filter if
         * there are any junk attrs in the top-level tlist.
         */
        if (operation == CMD_SELECT)
        {
                bool            junk_filter_needed = false;
                ListCell   *tlist;

                foreach(tlist, plan->targetlist)
                {
                        TargetEntry *tle = (TargetEntry *) lfirst(tlist);

                        if (tle->resjunk)
                        {
                                junk_filter_needed = true;
                                break;
                        }
                }

                if (junk_filter_needed)
                {
                        JunkFilter *j;
                        TupleTableSlot *slot;

                        slot = ExecInitExtraTupleSlot(estate, NULL, &TTSOpsVirtual);
                        j = ExecInitJunkFilter(planstate->plan->targetlist,
                                                                   slot);
                        estate->es_junkFilter = j;

                        /* Want to return the cleaned tuple type */
                        tupType = j->jf_cleanTupType;
                }
        }

        queryDesc->tupDesc = tupType;
        queryDesc->planstate = planstate;
}

/*
 * Check that a proposed result relation is a legal target for the operation
 *
 * Generally the parser and/or planner should have noticed any such mistake
 * already, but let's make sure.
 *
 * For MERGE, mergeActions is the list of actions that may be performed.  The
 * result relation is required to support every action, regardless of whether
 * or not they are all executed.
 *
 * Note: when changing this function, you probably also need to look at
 * CheckValidRowMarkRel.
 */
void
CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
                                        List *mergeActions)
{
        Relation        resultRel = resultRelInfo->ri_RelationDesc;
        FdwRoutine *fdwroutine;

        /* Expect a fully-formed ResultRelInfo from InitResultRelInfo(). */
        Assert(resultRelInfo->ri_needLockTagTuple ==
                   IsInplaceUpdateRelation(resultRel));

        switch (resultRel->rd_rel->relkind)
        {
                case RELKIND_RELATION:
                case RELKIND_PARTITIONED_TABLE:
                        CheckCmdReplicaIdentity(resultRel, operation);
                        break;
                case RELKIND_SEQUENCE:
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot change sequence \"%s\"",
                                                        RelationGetRelationName(resultRel))));
                        break;
                case RELKIND_TOASTVALUE:
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot change TOAST relation \"%s\"",
                                                        RelationGetRelationName(resultRel))));
                        break;
                case RELKIND_VIEW:

                        /*
                         * Okay only if there's a suitable INSTEAD OF trigger.  Otherwise,
                         * complain, but omit errdetail because we haven't got the
                         * information handy (and given that it really shouldn't happen,
                         * it's not worth great exertion to get).
                         */
                        if (!view_has_instead_trigger(resultRel, operation, mergeActions))
                                error_view_not_updatable(resultRel, operation, mergeActions,
                                                                                 NULL);
                        break;
                case RELKIND_MATVIEW:
                        if (!MatViewIncrementalMaintenanceIsEnabled())
                                ereport(ERROR,
                                                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                                 errmsg("cannot change materialized view \"%s\"",
                                                                RelationGetRelationName(resultRel))));
                        break;
                case RELKIND_FOREIGN_TABLE:
                        /* Okay only if the FDW supports it */
                        fdwroutine = resultRelInfo->ri_FdwRoutine;
                        switch (operation)
                        {
                                case CMD_INSERT:
                                        if (fdwroutine->ExecForeignInsert == NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                                                 errmsg("cannot insert into foreign table \"%s\"",
                                                                                RelationGetRelationName(resultRel))));
                                        if (fdwroutine->IsForeignRelUpdatable != NULL &&
                                                (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_INSERT)) == 0)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                                                                 errmsg("foreign table \"%s\" does not allow inserts",
                                                                                RelationGetRelationName(resultRel))));
                                        break;
                                case CMD_UPDATE:
                                        if (fdwroutine->ExecForeignUpdate == NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                                                 errmsg("cannot update foreign table \"%s\"",
                                                                                RelationGetRelationName(resultRel))));
                                        if (fdwroutine->IsForeignRelUpdatable != NULL &&
                                                (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_UPDATE)) == 0)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                                                                 errmsg("foreign table \"%s\" does not allow updates",
                                                                                RelationGetRelationName(resultRel))));
                                        break;
                                case CMD_DELETE:
                                        if (fdwroutine->ExecForeignDelete == NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                                                 errmsg("cannot delete from foreign table \"%s\"",
                                                                                RelationGetRelationName(resultRel))));
                                        if (fdwroutine->IsForeignRelUpdatable != NULL &&
                                                (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_DELETE)) == 0)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                                                                 errmsg("foreign table \"%s\" does not allow deletes",
                                                                                RelationGetRelationName(resultRel))));
                                        break;
                                default:
                                        elog(ERROR, "unrecognized CmdType: %d", (int) operation);
                                        break;
                        }
                        break;
                default:
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot change relation \"%s\"",
                                                        RelationGetRelationName(resultRel))));
                        break;
        }
}

/*
 * Check that a proposed rowmark target relation is a legal target
 *
 * In most cases parser and/or planner should have noticed this already, but
 * they don't cover all cases.
 */
static void
CheckValidRowMarkRel(Relation rel, RowMarkType markType)
{
        FdwRoutine *fdwroutine;

        switch (rel->rd_rel->relkind)
        {
                case RELKIND_RELATION:
                case RELKIND_PARTITIONED_TABLE:
                        /* OK */
                        break;
                case RELKIND_SEQUENCE:
                        /* Must disallow this because we don't vacuum sequences */
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot lock rows in sequence \"%s\"",
                                                        RelationGetRelationName(rel))));
                        break;
                case RELKIND_TOASTVALUE:
                        /* We could allow this, but there seems no good reason to */
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot lock rows in TOAST relation \"%s\"",
                                                        RelationGetRelationName(rel))));
                        break;
                case RELKIND_VIEW:
                        /* Should not get here; planner should have expanded the view */
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot lock rows in view \"%s\"",
                                                        RelationGetRelationName(rel))));
                        break;
                case RELKIND_MATVIEW:
                        /* Allow referencing a matview, but not actual locking clauses */
                        if (markType != ROW_MARK_REFERENCE)
                                ereport(ERROR,
                                                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                                 errmsg("cannot lock rows in materialized view \"%s\"",
                                                                RelationGetRelationName(rel))));
                        break;
                case RELKIND_FOREIGN_TABLE:
                        /* Okay only if the FDW supports it */
                        fdwroutine = GetFdwRoutineForRelation(rel, false);
                        if (fdwroutine->RefetchForeignRow == NULL)
                                ereport(ERROR,
                                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                                 errmsg("cannot lock rows in foreign table \"%s\"",
                                                                RelationGetRelationName(rel))));
                        break;
                default:
                        ereport(ERROR,
                                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                                         errmsg("cannot lock rows in relation \"%s\"",
                                                        RelationGetRelationName(rel))));
                        break;
        }
}

/*
 * Initialize ResultRelInfo data for one result relation
 *
 * Caution: before Postgres 9.1, this function included the relkind checking
 * that's now in CheckValidResultRel, and it also did ExecOpenIndices if
 * appropriate.  Be sure callers cover those needs.
 */
void
InitResultRelInfo(ResultRelInfo *resultRelInfo,
                                  Relation resultRelationDesc,
                                  Index resultRelationIndex,
                                  ResultRelInfo *partition_root_rri,
                                  int instrument_options)
{
        MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
        resultRelInfo->type = T_ResultRelInfo;
        resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
        resultRelInfo->ri_RelationDesc = resultRelationDesc;
        resultRelInfo->ri_NumIndices = 0;
        resultRelInfo->ri_IndexRelationDescs = NULL;
        resultRelInfo->ri_IndexRelationInfo = NULL;
        resultRelInfo->ri_needLockTagTuple =
                IsInplaceUpdateRelation(resultRelationDesc);
        /* make a copy so as not to depend on relcache info not changing... */
        resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
        if (resultRelInfo->ri_TrigDesc)
        {
                int                     n = resultRelInfo->ri_TrigDesc->numtriggers;

                resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
                        palloc0(n * sizeof(FmgrInfo));
                resultRelInfo->ri_TrigWhenExprs = (ExprState **)
                        palloc0(n * sizeof(ExprState *));
                if (instrument_options)
                        resultRelInfo->ri_TrigInstrument = InstrAlloc(n, instrument_options, false);
        }
        else
        {
                resultRelInfo->ri_TrigFunctions = NULL;
                resultRelInfo->ri_TrigWhenExprs = NULL;
                resultRelInfo->ri_TrigInstrument = NULL;
        }
        if (resultRelationDesc->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
                resultRelInfo->ri_FdwRoutine = GetFdwRoutineForRelation(resultRelationDesc, true);
        else
                resultRelInfo->ri_FdwRoutine = NULL;

        /* The following fields are set later if needed */
        resultRelInfo->ri_RowIdAttNo = 0;
        resultRelInfo->ri_extraUpdatedCols = NULL;
        resultRelInfo->ri_projectNew = NULL;
        resultRelInfo->ri_newTupleSlot = NULL;
        resultRelInfo->ri_oldTupleSlot = NULL;
        resultRelInfo->ri_projectNewInfoValid = false;
        resultRelInfo->ri_FdwState = NULL;
        resultRelInfo->ri_usesFdwDirectModify = false;
        resultRelInfo->ri_ConstraintExprs = NULL;
        resultRelInfo->ri_GeneratedExprsI = NULL;
        resultRelInfo->ri_GeneratedExprsU = NULL;
        resultRelInfo->ri_projectReturning = NULL;
        resultRelInfo->ri_onConflictArbiterIndexes = NIL;
        resultRelInfo->ri_onConflict = NULL;
        resultRelInfo->ri_ReturningSlot = NULL;
        resultRelInfo->ri_TrigOldSlot = NULL;
        resultRelInfo->ri_TrigNewSlot = NULL;
        resultRelInfo->ri_AllNullSlot = NULL;
        resultRelInfo->ri_MergeActions[MERGE_WHEN_MATCHED] = NIL;
        resultRelInfo->ri_MergeActions[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = NIL;
        resultRelInfo->ri_MergeActions[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = NIL;
        resultRelInfo->ri_MergeJoinCondition = NULL;

        /*
         * Only ExecInitPartitionInfo() and ExecInitPartitionDispatchInfo() pass
         * non-NULL partition_root_rri.  For child relations that are part of the
         * initial query rather than being dynamically added by tuple routing,
         * this field is filled in ExecInitModifyTable().
         */
        resultRelInfo->ri_RootResultRelInfo = partition_root_rri;
        /* Set by ExecGetRootToChildMap */
        resultRelInfo->ri_RootToChildMap = NULL;
        resultRelInfo->ri_RootToChildMapValid = false;
        /* Set by ExecInitRoutingInfo */
        resultRelInfo->ri_PartitionTupleSlot = NULL;
        resultRelInfo->ri_ChildToRootMap = NULL;
        resultRelInfo->ri_ChildToRootMapValid = false;
        resultRelInfo->ri_CopyMultiInsertBuffer = NULL;
}

/*
 * ExecGetTriggerResultRel
 *              Get a ResultRelInfo for a trigger target relation.
 *
 * Most of the time, triggers are fired on one of the result relations of the
 * query, and so we can just return a member of the es_result_relations array,
 * or the es_tuple_routing_result_relations list (if any). (Note: in self-join
 * situations there might be multiple members with the same OID; if so it
 * doesn't matter which one we pick.)
 *
 * However, it is sometimes necessary to fire triggers on other relations;
 * this happens mainly when an RI update trigger queues additional triggers
 * on other relations, which will be processed in the context of the outer
 * query.  For efficiency's sake, we want to have a ResultRelInfo for those
 * triggers too; that can avoid repeated re-opening of the relation.  (It
 * also provides a way for EXPLAIN ANALYZE to report the runtimes of such
 * triggers.)  So we make additional ResultRelInfo's as needed, and save them
 * in es_trig_target_relations.
 */
ResultRelInfo *
ExecGetTriggerResultRel(EState *estate, Oid relid,
                                                ResultRelInfo *rootRelInfo)
{
        ResultRelInfo *rInfo;
        ListCell   *l;
        Relation        rel;
        MemoryContext oldcontext;

        /* Search through the query result relations */
        foreach(l, estate->es_opened_result_relations)
        {
                rInfo = lfirst(l);
                if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
                        return rInfo;
        }

        /*
         * Search through the result relations that were created during tuple
         * routing, if any.
         */
        foreach(l, estate->es_tuple_routing_result_relations)
        {
                rInfo = (ResultRelInfo *) lfirst(l);
                if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
                        return rInfo;
        }

        /* Nope, but maybe we already made an extra ResultRelInfo for it */
        foreach(l, estate->es_trig_target_relations)
        {
                rInfo = (ResultRelInfo *) lfirst(l);
                if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
                        return rInfo;
        }
        /* Nope, so we need a new one */

        /*
         * Open the target relation's relcache entry.  We assume that an
         * appropriate lock is still held by the backend from whenever the trigger
         * event got queued, so we need take no new lock here.  Also, we need not
         * recheck the relkind, so no need for CheckValidResultRel.
         */
        rel = table_open(relid, NoLock);

        /*
         * Make the new entry in the right context.
         */
        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
        rInfo = makeNode(ResultRelInfo);
        InitResultRelInfo(rInfo,
                                          rel,
                                          0,            /* dummy rangetable index */
                                          rootRelInfo,
                                          estate->es_instrument);
        estate->es_trig_target_relations =
                lappend(estate->es_trig_target_relations, rInfo);
        MemoryContextSwitchTo(oldcontext);

        /*
         * Currently, we don't need any index information in ResultRelInfos used
         * only for triggers, so no need to call ExecOpenIndices.
         */

        return rInfo;
}

/*
 * Return the ancestor relations of a given leaf partition result relation
 * up to and including the query's root target relation.
 *
 * These work much like the ones opened by ExecGetTriggerResultRel, except
 * that we need to keep them in a separate list.
 *
 * These are closed by ExecCloseResultRelations.
 */
List *
ExecGetAncestorResultRels(EState *estate, ResultRelInfo *resultRelInfo)
{
        ResultRelInfo *rootRelInfo = resultRelInfo->ri_RootResultRelInfo;
        Relation        partRel = resultRelInfo->ri_RelationDesc;
        Oid                     rootRelOid;

        if (!partRel->rd_rel->relispartition)
                elog(ERROR, "cannot find ancestors of a non-partition result relation");
        Assert(rootRelInfo != NULL);
        rootRelOid = RelationGetRelid(rootRelInfo->ri_RelationDesc);
        if (resultRelInfo->ri_ancestorResultRels == NIL)
        {
                ListCell   *lc;
                List       *oids = get_partition_ancestors(RelationGetRelid(partRel));
                List       *ancResultRels = NIL;

                foreach(lc, oids)
                {
                        Oid                     ancOid = lfirst_oid(lc);
                        Relation        ancRel;
                        ResultRelInfo *rInfo;

                        /*
                         * Ignore the root ancestor here, and use ri_RootResultRelInfo
                         * (below) for it instead.  Also, we stop climbing up the
                         * hierarchy when we find the table that was mentioned in the
                         * query.
                         */
                        if (ancOid == rootRelOid)
                                break;

                        /*
                         * All ancestors up to the root target relation must have been
                         * locked by the planner or AcquireExecutorLocks().
                         */
                        ancRel = table_open(ancOid, NoLock);
                        rInfo = makeNode(ResultRelInfo);

                        /* dummy rangetable index */
                        InitResultRelInfo(rInfo, ancRel, 0, NULL,
                                                          estate->es_instrument);
                        ancResultRels = lappend(ancResultRels, rInfo);
                }
                ancResultRels = lappend(ancResultRels, rootRelInfo);
                resultRelInfo->ri_ancestorResultRels = ancResultRels;
        }

        /* We must have found some ancestor */
        Assert(resultRelInfo->ri_ancestorResultRels != NIL);

        return resultRelInfo->ri_ancestorResultRels;
}

/* ----------------------------------------------------------------
 *              ExecPostprocessPlan
 *
 *              Give plan nodes a final chance to execute before shutdown
 * ----------------------------------------------------------------
 */
static void
ExecPostprocessPlan(EState *estate)
{
        ListCell   *lc;

        /*
         * Make sure nodes run forward.
         */
        estate->es_direction = ForwardScanDirection;

        /*
         * Run any secondary ModifyTable nodes to completion, in case the main
         * query did not fetch all rows from them.  (We do this to ensure that
         * such nodes have predictable results.)
         */
        foreach(lc, estate->es_auxmodifytables)
        {
                PlanState  *ps = (PlanState *) lfirst(lc);

                for (;;)
                {
                        TupleTableSlot *slot;

                        /* Reset the per-output-tuple exprcontext each time */
                        ResetPerTupleExprContext(estate);

                        slot = ExecProcNode(ps);

                        if (TupIsNull(slot))
                                break;
                }
        }
}

/* ----------------------------------------------------------------
 *              ExecEndPlan
 *
 *              Cleans up the query plan -- closes files and frees up storage
 *
 * NOTE: we are no longer very worried about freeing storage per se
 * in this code; FreeExecutorState should be guaranteed to release all
 * memory that needs to be released.  What we are worried about doing
 * is closing relations and dropping buffer pins.  Thus, for example,
 * tuple tables must be cleared or dropped to ensure pins are released.
 * ----------------------------------------------------------------
 */
static void
ExecEndPlan(PlanState *planstate, EState *estate)
{
        ListCell   *l;

        /*
         * shut down the node-type-specific query processing
         */
        ExecEndNode(planstate);

        /*
         * for subplans too
         */
        foreach(l, estate->es_subplanstates)
        {
                PlanState  *subplanstate = (PlanState *) lfirst(l);

                ExecEndNode(subplanstate);
        }

        /*
         * destroy the executor's tuple table.  Actually we only care about
         * releasing buffer pins and tupdesc refcounts; there's no need to pfree
         * the TupleTableSlots, since the containing memory context is about to go
         * away anyway.
         */
        ExecResetTupleTable(estate->es_tupleTable, false);

        /*
         * Close any Relations that have been opened for range table entries or
         * result relations.
         */
        ExecCloseResultRelations(estate);
        ExecCloseRangeTableRelations(estate);
}

/*
 * Close any relations that have been opened for ResultRelInfos.
 */
void
ExecCloseResultRelations(EState *estate)
{
        ListCell   *l;

        /*
         * close indexes of result relation(s) if any.  (Rels themselves are
         * closed in ExecCloseRangeTableRelations())
         *
         * In addition, close the stub RTs that may be in each resultrel's
         * ri_ancestorResultRels.
         */
        foreach(l, estate->es_opened_result_relations)
        {
                ResultRelInfo *resultRelInfo = lfirst(l);
                ListCell   *lc;

                ExecCloseIndices(resultRelInfo);
                foreach(lc, resultRelInfo->ri_ancestorResultRels)
                {
                        ResultRelInfo *rInfo = lfirst(lc);

                        /*
                         * Ancestors with RTI > 0 (should only be the root ancestor) are
                         * closed by ExecCloseRangeTableRelations.
                         */
                        if (rInfo->ri_RangeTableIndex > 0)
                                continue;

                        table_close(rInfo->ri_RelationDesc, NoLock);
                }
        }

        /* Close any relations that have been opened by ExecGetTriggerResultRel(). */
        foreach(l, estate->es_trig_target_relations)
        {
                ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);

                /*
                 * Assert this is a "dummy" ResultRelInfo, see above.  Otherwise we
                 * might be issuing a duplicate close against a Relation opened by
                 * ExecGetRangeTableRelation.
                 */
                Assert(resultRelInfo->ri_RangeTableIndex == 0);

                /*
                 * Since ExecGetTriggerResultRel doesn't call ExecOpenIndices for
                 * these rels, we needn't call ExecCloseIndices either.
                 */
                Assert(resultRelInfo->ri_NumIndices == 0);

                table_close(resultRelInfo->ri_RelationDesc, NoLock);
        }
}

/*
 * Close all relations opened by ExecGetRangeTableRelation().
 *
 * We do not release any locks we might hold on those rels.
 */
void
ExecCloseRangeTableRelations(EState *estate)
{
        int                     i;

        for (i = 0; i < estate->es_range_table_size; i++)
        {
                if (estate->es_relations[i])
                        table_close(estate->es_relations[i], NoLock);
        }
}

/* ----------------------------------------------------------------
 *              ExecutePlan
 *
 *              Processes the query plan until we have retrieved 'numberTuples' tuples,
 *              moving in the specified direction.
 *
 *              Runs to completion if numberTuples is 0
 * ----------------------------------------------------------------
 */
static void
ExecutePlan(QueryDesc *queryDesc,
                        CmdType operation,
                        bool sendTuples,
                        uint64 numberTuples,
                        ScanDirection direction,
                        DestReceiver *dest)
{
        EState     *estate = queryDesc->estate;
        PlanState  *planstate = queryDesc->planstate;
        bool            use_parallel_mode;
        TupleTableSlot *slot;
        uint64          current_tuple_count;

        /*
         * initialize local variables
         */
        current_tuple_count = 0;

        /*
         * Set the direction.
         */
        estate->es_direction = direction;

        /*
         * Set up parallel mode if appropriate.
         *
         * Parallel mode only supports complete execution of a plan.  If we've
         * already partially executed it, or if the caller asks us to exit early,
         * we must force the plan to run without parallelism.
         */
        if (queryDesc->already_executed || numberTuples != 0)
                use_parallel_mode = false;
        else
                use_parallel_mode = queryDesc->plannedstmt->parallelModeNeeded;
        queryDesc->already_executed = true;

        estate->es_use_parallel_mode = use_parallel_mode;
        if (use_parallel_mode)
                EnterParallelMode();

        /*
         * Loop until we've processed the proper number of tuples from the plan.
         */
        for (;;)
        {
                /* Reset the per-output-tuple exprcontext */
                ResetPerTupleExprContext(estate);

                /*
                 * Execute the plan and obtain a tuple
                 */
                slot = ExecProcNode(planstate);

                /*
                 * if the tuple is null, then we assume there is nothing more to
                 * process so we just end the loop...
                 */
                if (TupIsNull(slot))
                        break;

                /*
                 * If we have a junk filter, then project a new tuple with the junk
                 * removed.
                 *
                 * Store this new "clean" tuple in the junkfilter's resultSlot.
                 * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
                 * because that tuple slot has the wrong descriptor.)
                 */
                if (estate->es_junkFilter != NULL)
                        slot = ExecFilterJunk(estate->es_junkFilter, slot);

                /*
                 * If we are supposed to send the tuple somewhere, do so. (In
                 * practice, this is probably always the case at this point.)
                 */
                if (sendTuples)
                {
                        /*
                         * If we are not able to send the tuple, we assume the destination
                         * has closed and no more tuples can be sent. If that's the case,
                         * end the loop.
                         */
                        if (!dest->receiveSlot(slot, dest))
                                break;
                }

                /*
                 * Count tuples processed, if this is a SELECT.  (For other operation
                 * types, the ModifyTable plan node must count the appropriate
                 * events.)
                 */
                if (operation == CMD_SELECT)
                        (estate->es_processed)++;

                /*
                 * check our tuple count.. if we've processed the proper number then
                 * quit, else loop again and process more tuples.  Zero numberTuples
                 * means no limit.
                 */
                current_tuple_count++;
                if (numberTuples && numberTuples == current_tuple_count)
                        break;
        }

        /*
         * If we know we won't need to back up, we can release resources at this
         * point.
         */
        if (!(estate->es_top_eflags & EXEC_FLAG_BACKWARD))
                ExecShutdownNode(planstate);

        if (use_parallel_mode)
                ExitParallelMode();
}


/*
 * ExecRelCheck --- check that tuple meets constraints for result relation
 *
 * Returns NULL if OK, else name of failed check constraint
 */
static const char *
ExecRelCheck(ResultRelInfo *resultRelInfo,
                         TupleTableSlot *slot, EState *estate)
{
        Relation        rel = resultRelInfo->ri_RelationDesc;
        int                     ncheck = rel->rd_att->constr->num_check;
        ConstrCheck *check = rel->rd_att->constr->check;
        ExprContext *econtext;
        MemoryContext oldContext;
        int                     i;

        /*
         * CheckConstraintFetch let this pass with only a warning, but now we
         * should fail rather than possibly failing to enforce an important
         * constraint.
         */
        if (ncheck != rel->rd_rel->relchecks)
                elog(ERROR, "%d pg_constraint record(s) missing for relation \"%s\"",
                         rel->rd_rel->relchecks - ncheck, RelationGetRelationName(rel));

        /*
         * If first time through for this result relation, build expression
         * nodetrees for rel's constraint expressions.  Keep them in the per-query
         * memory context so they'll survive throughout the query.
         */
        if (resultRelInfo->ri_ConstraintExprs == NULL)
        {
                oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
                resultRelInfo->ri_ConstraintExprs =
                        (ExprState **) palloc0(ncheck * sizeof(ExprState *));
                for (i = 0; i < ncheck; i++)
                {
                        Expr       *checkconstr;

                        /* Skip not enforced constraint */
                        if (!check[i].ccenforced)
                                continue;

                        checkconstr = stringToNode(check[i].ccbin);
                        resultRelInfo->ri_ConstraintExprs[i] =
                                ExecPrepareExpr(checkconstr, estate);
                }
                MemoryContextSwitchTo(oldContext);
        }

        /*
         * We will use the EState's per-tuple context for evaluating constraint
         * expressions (creating it if it's not already there).
         */
        econtext = GetPerTupleExprContext(estate);

        /* Arrange for econtext's scan tuple to be the tuple under test */
        econtext->ecxt_scantuple = slot;

        /* And evaluate the constraints */
        for (i = 0; i < ncheck; i++)
        {
                ExprState  *checkconstr = resultRelInfo->ri_ConstraintExprs[i];

                /*
                 * NOTE: SQL specifies that a NULL result from a constraint expression
                 * is not to be treated as a failure.  Therefore, use ExecCheck not
                 * ExecQual.
                 */
                if (checkconstr && !ExecCheck(checkconstr, econtext))
                        return check[i].ccname;
        }

        /* NULL result means no error */
        return NULL;
}

/*
 * ExecPartitionCheck --- check that tuple meets the partition constraint.
 *
 * Returns true if it meets the partition constraint.  If the constraint
 * fails and we're asked to emit an error, do so and don't return; otherwise
 * return false.
 */
bool
ExecPartitionCheck(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
                                   EState *estate, bool emitError)
{
        ExprContext *econtext;
        bool            success;

        /*
         * If first time through, build expression state tree for the partition
         * check expression.  (In the corner case where the partition check
         * expression is empty, ie there's a default partition and nothing else,
         * we'll be fooled into executing this code each time through.  But it's
         * pretty darn cheap in that case, so we don't worry about it.)
         */
        if (resultRelInfo->ri_PartitionCheckExpr == NULL)
        {
                /*
                 * Ensure that the qual tree and prepared expression are in the
                 * query-lifespan context.
                 */
                MemoryContext oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
                List       *qual = RelationGetPartitionQual(resultRelInfo->ri_RelationDesc);

                resultRelInfo->ri_PartitionCheckExpr = ExecPrepareCheck(qual, estate);
                MemoryContextSwitchTo(oldcxt);
        }

        /*
         * We will use the EState's per-tuple context for evaluating constraint
         * expressions (creating it if it's not already there).
         */
        econtext = GetPerTupleExprContext(estate);

        /* Arrange for econtext's scan tuple to be the tuple under test */
        econtext->ecxt_scantuple = slot;

        /*
         * As in case of the cataloged constraints, we treat a NULL result as
         * success here, not a failure.
         */
        success = ExecCheck(resultRelInfo->ri_PartitionCheckExpr, econtext);

        /* if asked to emit error, don't actually return on failure */
        if (!success && emitError)
                ExecPartitionCheckEmitError(resultRelInfo, slot, estate);

        return success;
}

/*
 * ExecPartitionCheckEmitError - Form and emit an error message after a failed
 * partition constraint check.
 */
void
ExecPartitionCheckEmitError(ResultRelInfo *resultRelInfo,
                                                        TupleTableSlot *slot,
                                                        EState *estate)
{
        Oid                     root_relid;
        TupleDesc       tupdesc;
        char       *val_desc;
        Bitmapset  *modifiedCols;

        /*
         * If the tuple has been routed, it's been converted to the partition's
         * rowtype, which might differ from the root table's.  We must convert it
         * back to the root table's rowtype so that val_desc in the error message
         * matches the input tuple.
         */
        if (resultRelInfo->ri_RootResultRelInfo)
        {
                ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
                TupleDesc       old_tupdesc;
                AttrMap    *map;

                root_relid = RelationGetRelid(rootrel->ri_RelationDesc);
                tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);

                old_tupdesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
                /* a reverse map */
                map = build_attrmap_by_name_if_req(old_tupdesc, tupdesc, false);

                /*
                 * Partition-specific slot's tupdesc can't be changed, so allocate a
                 * new one.
                 */
                if (map != NULL)
                        slot = execute_attr_map_slot(map, slot,
                                                                                 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
                modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
                                                                 ExecGetUpdatedCols(rootrel, estate));
        }
        else
        {
                root_relid = RelationGetRelid(resultRelInfo->ri_RelationDesc);
                tupdesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
                modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
                                                                 ExecGetUpdatedCols(resultRelInfo, estate));
        }

        val_desc = ExecBuildSlotValueDescription(root_relid,
                                                                                         slot,
                                                                                         tupdesc,
                                                                                         modifiedCols,
                                                                                         64);
        ereport(ERROR,
                        (errcode(ERRCODE_CHECK_VIOLATION),
                         errmsg("new row for relation \"%s\" violates partition constraint",
                                        RelationGetRelationName(resultRelInfo->ri_RelationDesc)),
                         val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
                         errtable(resultRelInfo->ri_RelationDesc)));
}

/*
 * ExecConstraints - check constraints of the tuple in 'slot'
 *
 * This checks the traditional NOT NULL and check constraints.
 *
 * The partition constraint is *NOT* checked.
 *
 * Note: 'slot' contains the tuple to check the constraints of, which may
 * have been converted from the original input tuple after tuple routing.
 * 'resultRelInfo' is the final result relation, after tuple routing.
 */
void
ExecConstraints(ResultRelInfo *resultRelInfo,
                                TupleTableSlot *slot, EState *estate)
{
        Relation        rel = resultRelInfo->ri_RelationDesc;
        TupleDesc       tupdesc = RelationGetDescr(rel);
        TupleConstr *constr = tupdesc->constr;
        Bitmapset  *modifiedCols;

        Assert(constr);                         /* we should not be called otherwise */

        if (constr->has_not_null)
        {
                int                     natts = tupdesc->natts;
                int                     attrChk;

                for (attrChk = 1; attrChk <= natts; attrChk++)
                {
                        Form_pg_attribute att = TupleDescAttr(tupdesc, attrChk - 1);

                        if (att->attnotnull && slot_attisnull(slot, attrChk))
                        {
                                char       *val_desc;
                                Relation        orig_rel = rel;
                                TupleDesc       orig_tupdesc = RelationGetDescr(rel);

                                /*
                                 * If the tuple has been routed, it's been converted to the
                                 * partition's rowtype, which might differ from the root
                                 * table's.  We must convert it back to the root table's
                                 * rowtype so that val_desc shown error message matches the
                                 * input tuple.
                                 */
                                if (resultRelInfo->ri_RootResultRelInfo)
                                {
                                        ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
                                        AttrMap    *map;

                                        tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
                                        /* a reverse map */
                                        map = build_attrmap_by_name_if_req(orig_tupdesc,
                                                                                                           tupdesc,
                                                                                                           false);

                                        /*
                                         * Partition-specific slot's tupdesc can't be changed, so
                                         * allocate a new one.
                                         */
                                        if (map != NULL)
                                                slot = execute_attr_map_slot(map, slot,
                                                                                                         MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
                                        modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
                                                                                         ExecGetUpdatedCols(rootrel, estate));
                                        rel = rootrel->ri_RelationDesc;
                                }
                                else
                                        modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
                                                                                         ExecGetUpdatedCols(resultRelInfo, estate));
                                val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
                                                                                                                 slot,
                                                                                                                 tupdesc,
                                                                                                                 modifiedCols,
                                                                                                                 64);

                                ereport(ERROR,
                                                (errcode(ERRCODE_NOT_NULL_VIOLATION),
                                                 errmsg("null value in column \"%s\" of relation \"%s\" violates not-null constraint",
                                                                NameStr(att->attname),
                                                                RelationGetRelationName(orig_rel)),
                                                 val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
                                                 errtablecol(orig_rel, attrChk)));
                        }
                }
        }

        if (rel->rd_rel->relchecks > 0)
        {
                const char *failed;

                if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
                {
                        char       *val_desc;
                        Relation        orig_rel = rel;

                        /* See the comment above. */
                        if (resultRelInfo->ri_RootResultRelInfo)
                        {
                                ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
                                TupleDesc       old_tupdesc = RelationGetDescr(rel);
                                AttrMap    *map;

                                tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
                                /* a reverse map */
                                map = build_attrmap_by_name_if_req(old_tupdesc,
                                                                                                   tupdesc,
                                                                                                   false);

                                /*
                                 * Partition-specific slot's tupdesc can't be changed, so
                                 * allocate a new one.
                                 */
                                if (map != NULL)
                                        slot = execute_attr_map_slot(map, slot,
                                                                                                 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
                                modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
                                                                                 ExecGetUpdatedCols(rootrel, estate));
                                rel = rootrel->ri_RelationDesc;
                        }
                        else
                                modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
                                                                                 ExecGetUpdatedCols(resultRelInfo, estate));
                        val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
                                                                                                         slot,
                                                                                                         tupdesc,
                                                                                                         modifiedCols,
                                                                                                         64);
                        ereport(ERROR,
                                        (errcode(ERRCODE_CHECK_VIOLATION),
                                         errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
                                                        RelationGetRelationName(orig_rel), failed),
                                         val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
                                         errtableconstraint(orig_rel, failed)));
                }
        }
}

/*
 * ExecWithCheckOptions -- check that tuple satisfies any WITH CHECK OPTIONs
 * of the specified kind.
 *
 * Note that this needs to be called multiple times to ensure that all kinds of
 * WITH CHECK OPTIONs are handled (both those from views which have the WITH
 * CHECK OPTION set and from row-level security policies).  See ExecInsert()
 * and ExecUpdate().
 */
void
ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
                                         TupleTableSlot *slot, EState *estate)
{
        Relation        rel = resultRelInfo->ri_RelationDesc;
        TupleDesc       tupdesc = RelationGetDescr(rel);
        ExprContext *econtext;
        ListCell   *l1,
                           *l2;

        /*
         * We will use the EState's per-tuple context for evaluating constraint
         * expressions (creating it if it's not already there).
         */
        econtext = GetPerTupleExprContext(estate);

        /* Arrange for econtext's scan tuple to be the tuple under test */
        econtext->ecxt_scantuple = slot;

        /* Check each of the constraints */
        forboth(l1, resultRelInfo->ri_WithCheckOptions,
                        l2, resultRelInfo->ri_WithCheckOptionExprs)
        {
                WithCheckOption *wco = (WithCheckOption *) lfirst(l1);
                ExprState  *wcoExpr = (ExprState *) lfirst(l2);

                /*
                 * Skip any WCOs which are not the kind we are looking for at this
                 * time.
                 */
                if (wco->kind != kind)
                        continue;

                /*
                 * WITH CHECK OPTION checks are intended to ensure that the new tuple
                 * is visible (in the case of a view) or that it passes the
                 * 'with-check' policy (in the case of row security). If the qual
                 * evaluates to NULL or FALSE, then the new tuple won't be included in
                 * the view or doesn't pass the 'with-check' policy for the table.
                 */
                if (!ExecQual(wcoExpr, econtext))
                {
                        char       *val_desc;
                        Bitmapset  *modifiedCols;

                        switch (wco->kind)
                        {
                                        /*
                                         * For WITH CHECK OPTIONs coming from views, we might be
                                         * able to provide the details on the row, depending on
                                         * the permissions on the relation (that is, if the user
                                         * could view it directly anyway).  For RLS violations, we
                                         * don't include the data since we don't know if the user
                                         * should be able to view the tuple as that depends on the
                                         * USING policy.
                                         */
                                case WCO_VIEW_CHECK:
                                        /* See the comment in ExecConstraints(). */
                                        if (resultRelInfo->ri_RootResultRelInfo)
                                        {
                                                ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
                                                TupleDesc       old_tupdesc = RelationGetDescr(rel);
                                                AttrMap    *map;

                                                tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
                                                /* a reverse map */
                                                map = build_attrmap_by_name_if_req(old_tupdesc,
                                                                                                                   tupdesc,
                                                                                                                   false);

                                                /*
                                                 * Partition-specific slot's tupdesc can't be changed,
                                                 * so allocate a new one.
                                                 */
                                                if (map != NULL)
                                                        slot = execute_attr_map_slot(map, slot,
                                                                                                                 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));

                                                modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
                                                                                                 ExecGetUpdatedCols(rootrel, estate));
                                                rel = rootrel->ri_RelationDesc;
                                        }
                                        else
                                                modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
                                                                                                 ExecGetUpdatedCols(resultRelInfo, estate));
                                        val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
                                                                                                                         slot,
                                                                                                                         tupdesc,
                                                                                                                         modifiedCols,
                                                                                                                         64);

                                        ereport(ERROR,
                                                        (errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
                                                         errmsg("new row violates check option for view \"%s\"",
                                                                        wco->relname),
                                                         val_desc ? errdetail("Failing row contains %s.",
                                                                                                  val_desc) : 0));
                                        break;
                                case WCO_RLS_INSERT_CHECK:
                                case WCO_RLS_UPDATE_CHECK:
                                        if (wco->polname != NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("new row violates row-level security policy \"%s\" for table \"%s\"",
                                                                                wco->polname, wco->relname)));
                                        else
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("new row violates row-level security policy for table \"%s\"",
                                                                                wco->relname)));
                                        break;
                                case WCO_RLS_MERGE_UPDATE_CHECK:
                                case WCO_RLS_MERGE_DELETE_CHECK:
                                        if (wco->polname != NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("target row violates row-level security policy \"%s\" (USING expression) for table \"%s\"",
                                                                                wco->polname, wco->relname)));
                                        else
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("target row violates row-level security policy (USING expression) for table \"%s\"",
                                                                                wco->relname)));
                                        break;
                                case WCO_RLS_CONFLICT_CHECK:
                                        if (wco->polname != NULL)
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("new row violates row-level security policy \"%s\" (USING expression) for table \"%s\"",
                                                                                wco->polname, wco->relname)));
                                        else
                                                ereport(ERROR,
                                                                (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                                                 errmsg("new row violates row-level security policy (USING expression) for table \"%s\"",
                                                                                wco->relname)));
                                        break;
                                default:
                                        elog(ERROR, "unrecognized WCO kind: %u", wco->kind);
                                        break;
                        }
                }
        }
}

/*
 * ExecBuildSlotValueDescription -- construct a string representing a tuple
 *
 * This is intentionally very similar to BuildIndexValueDescription, but
 * unlike that function, we truncate long field values (to at most maxfieldlen
 * bytes).  That seems necessary here since heap field values could be very
 * long, whereas index entries typically aren't so wide.
 *
 * Also, unlike the case with index entries, we need to be prepared to ignore
 * dropped columns.  We used to use the slot's tuple descriptor to decode the
 * data, but the slot's descriptor doesn't identify dropped columns, so we
 * now need to be passed the relation's descriptor.
 *
 * Note that, like BuildIndexValueDescription, if the user does not have
 * permission to view any of the columns involved, a NULL is returned.  Unlike
 * BuildIndexValueDescription, if the user has access to view a subset of the
 * column involved, that subset will be returned with a key identifying which
 * columns they are.
 */
char *
ExecBuildSlotValueDescription(Oid reloid,
                                                          TupleTableSlot *slot,
                                                          TupleDesc tupdesc,
                                                          Bitmapset *modifiedCols,
                                                          int maxfieldlen)
{
        StringInfoData buf;
        StringInfoData collist;
        bool            write_comma = false;
        bool            write_comma_collist = false;
        int                     i;
        AclResult       aclresult;
        bool            table_perm = false;
        bool            any_perm = false;

        /*
         * Check if RLS is enabled and should be active for the relation; if so,
         * then don't return anything.  Otherwise, go through normal permission
         * checks.
         */
        if (check_enable_rls(reloid, InvalidOid, true) == RLS_ENABLED)
                return NULL;

        initStringInfo(&buf);

        appendStringInfoChar(&buf, '(');

        /*
         * Check if the user has permissions to see the row.  Table-level SELECT
         * allows access to all columns.  If the user does not have table-level
         * SELECT then we check each column and include those the user has SELECT
         * rights on.  Additionally, we always include columns the user provided
         * data for.
         */
        aclresult = pg_class_aclcheck(reloid, GetUserId(), ACL_SELECT);
        if (aclresult != ACLCHECK_OK)
        {
                /* Set up the buffer for the column list */
                initStringInfo(&collist);
                appendStringInfoChar(&collist, '(');
        }
        else
                table_perm = any_perm = true;

        /* Make sure the tuple is fully deconstructed */
        slot_getallattrs(slot);

        for (i = 0; i < tupdesc->natts; i++)
        {
                bool            column_perm = false;
                char       *val;
                int                     vallen;
                Form_pg_attribute att = TupleDescAttr(tupdesc, i);

                /* ignore dropped columns */
                if (att->attisdropped)
                        continue;

                if (!table_perm)
                {
                        /*
                         * No table-level SELECT, so need to make sure they either have
                         * SELECT rights on the column or that they have provided the data
                         * for the column.  If not, omit this column from the error
                         * message.
                         */
                        aclresult = pg_attribute_aclcheck(reloid, att->attnum,
                                                                                          GetUserId(), ACL_SELECT);
                        if (bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,
                                                          modifiedCols) || aclresult == ACLCHECK_OK)
                        {
                                column_perm = any_perm = true;

                                if (write_comma_collist)
                                        appendStringInfoString(&collist, ", ");
                                else
                                        write_comma_collist = true;

                                appendStringInfoString(&collist, NameStr(att->attname));
                        }
                }

                if (table_perm || column_perm)
                {
                        if (slot->tts_isnull[i])
                                val = "null";
                        else
                        {
                                Oid                     foutoid;
                                bool            typisvarlena;

                                getTypeOutputInfo(att->atttypid,
                                                                  &foutoid, &typisvarlena);
                                val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
                        }

                        if (write_comma)
                                appendStringInfoString(&buf, ", ");
                        else
                                write_comma = true;

                        /* truncate if needed */
                        vallen = strlen(val);
                        if (vallen <= maxfieldlen)
                                appendBinaryStringInfo(&buf, val, vallen);
                        else
                        {
                                vallen = pg_mbcliplen(val, vallen, maxfieldlen);
                                appendBinaryStringInfo(&buf, val, vallen);
                                appendStringInfoString(&buf, "...");
                        }
                }
        }

        /* If we end up with zero columns being returned, then return NULL. */
        if (!any_perm)
                return NULL;

        appendStringInfoChar(&buf, ')');

        if (!table_perm)
        {
                appendStringInfoString(&collist, ") = ");
                appendBinaryStringInfo(&collist, buf.data, buf.len);

                return collist.data;
        }

        return buf.data;
}


/*
 * ExecUpdateLockMode -- find the appropriate UPDATE tuple lock mode for a
 * given ResultRelInfo
 */
LockTupleMode
ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo)
{
        Bitmapset  *keyCols;
        Bitmapset  *updatedCols;

        /*
         * Compute lock mode to use.  If columns that are part of the key have not
         * been modified, then we can use a weaker lock, allowing for better
         * concurrency.
         */
        updatedCols = ExecGetAllUpdatedCols(relinfo, estate);
        keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc,
                                                                                 INDEX_ATTR_BITMAP_KEY);

        if (bms_overlap(keyCols, updatedCols))
                return LockTupleExclusive;

        return LockTupleNoKeyExclusive;
}

/*
 * ExecFindRowMark -- find the ExecRowMark struct for given rangetable index
 *
 * If no such struct, either return NULL or throw error depending on missing_ok
 */
ExecRowMark *
ExecFindRowMark(EState *estate, Index rti, bool missing_ok)
{
        if (rti > 0 && rti <= estate->es_range_table_size &&
                estate->es_rowmarks != NULL)
        {
                ExecRowMark *erm = estate->es_rowmarks[rti - 1];

                if (erm)
                        return erm;
        }
        if (!missing_ok)
                elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
        return NULL;
}

/*
 * ExecBuildAuxRowMark -- create an ExecAuxRowMark struct
 *
 * Inputs are the underlying ExecRowMark struct and the targetlist of the
 * input plan node (not planstate node!).  We need the latter to find out
 * the column numbers of the resjunk columns.
 */
ExecAuxRowMark *
ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
{
        ExecAuxRowMark *aerm = (ExecAuxRowMark *) palloc0(sizeof(ExecAuxRowMark));
        char            resname[32];

        aerm->rowmark = erm;

        /* Look up the resjunk columns associated with this rowmark */
        if (erm->markType != ROW_MARK_COPY)
        {
                /* need ctid for all methods other than COPY */
                snprintf(resname, sizeof(resname), "ctid%u", erm->rowmarkId);
                aerm->ctidAttNo = ExecFindJunkAttributeInTlist(targetlist,
                                                                                                           resname);
                if (!AttributeNumberIsValid(aerm->ctidAttNo))
                        elog(ERROR, "could not find junk %s column", resname);
        }
        else
        {
                /* need wholerow if COPY */
                snprintf(resname, sizeof(resname), "wholerow%u", erm->rowmarkId);
                aerm->wholeAttNo = ExecFindJunkAttributeInTlist(targetlist,
                                                                                                                resname);
                if (!AttributeNumberIsValid(aerm->wholeAttNo))
                        elog(ERROR, "could not find junk %s column", resname);
        }

        /* if child rel, need tableoid */
        if (erm->rti != erm->prti)
        {
                snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
                aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
                                                                                                           resname);
                if (!AttributeNumberIsValid(aerm->toidAttNo))
                        elog(ERROR, "could not find junk %s column", resname);
        }

        return aerm;
}


/*
 * EvalPlanQual logic --- recheck modified tuple(s) to see if we want to
 * process the updated version under READ COMMITTED rules.
 *
 * See backend/executor/README for some info about how this works.
 */


/*
 * Check the updated version of a tuple to see if we want to process it under
 * READ COMMITTED rules.
 *
 *      epqstate - state for EvalPlanQual rechecking
 *      relation - table containing tuple
 *      rti - rangetable index of table containing tuple
 *      inputslot - tuple for processing - this can be the slot from
 *              EvalPlanQualSlot() for this rel, for increased efficiency.
 *
 * This tests whether the tuple in inputslot still matches the relevant
 * quals. For that result to be useful, typically the input tuple has to be
 * last row version (otherwise the result isn't particularly useful) and
 * locked (otherwise the result might be out of date). That's typically
 * achieved by using table_tuple_lock() with the
 * TUPLE_LOCK_FLAG_FIND_LAST_VERSION flag.
 *
 * Returns a slot containing the new candidate update/delete tuple, or
 * NULL if we determine we shouldn't process the row.
 */
TupleTableSlot *
EvalPlanQual(EPQState *epqstate, Relation relation,
                         Index rti, TupleTableSlot *inputslot)
{
        TupleTableSlot *slot;
        TupleTableSlot *testslot;

        Assert(rti > 0);

        /*
         * Need to run a recheck subquery.  Initialize or reinitialize EPQ state.
         */
        EvalPlanQualBegin(epqstate);

        /*
         * Callers will often use the EvalPlanQualSlot to store the tuple to avoid
         * an unnecessary copy.
         */
        testslot = EvalPlanQualSlot(epqstate, relation, rti);
        if (testslot != inputslot)
                ExecCopySlot(testslot, inputslot);

        /*
         * Mark that an EPQ tuple is available for this relation.  (If there is
         * more than one result relation, the others remain marked as having no
         * tuple available.)
         */
        epqstate->relsubs_done[rti - 1] = false;
        epqstate->relsubs_blocked[rti - 1] = false;

        /*
         * Run the EPQ query.  We assume it will return at most one tuple.
         */
        slot = EvalPlanQualNext(epqstate);

        /*
         * If we got a tuple, force the slot to materialize the tuple so that it
         * is not dependent on any local state in the EPQ query (in particular,
         * it's highly likely that the slot contains references to any pass-by-ref
         * datums that may be present in copyTuple).  As with the next step, this
         * is to guard against early re-use of the EPQ query.
         */
        if (!TupIsNull(slot))
                ExecMaterializeSlot(slot);

        /*
         * Clear out the test tuple, and mark that no tuple is available here.
         * This is needed in case the EPQ state is re-used to test a tuple for a
         * different target relation.
         */
        ExecClearTuple(testslot);
        epqstate->relsubs_blocked[rti - 1] = true;

        return slot;
}

/*
 * EvalPlanQualInit -- initialize during creation of a plan state node
 * that might need to invoke EPQ processing.
 *
 * If the caller intends to use EvalPlanQual(), resultRelations should be
 * a list of RT indexes of potential target relations for EvalPlanQual(),
 * and we will arrange that the other listed relations don't return any
 * tuple during an EvalPlanQual() call.  Otherwise resultRelations
 * should be NIL.
 *
 * Note: subplan/auxrowmarks can be NULL/NIL if they will be set later
 * with EvalPlanQualSetPlan.
 */
void
EvalPlanQualInit(EPQState *epqstate, EState *parentestate,
                                 Plan *subplan, List *auxrowmarks,
                                 int epqParam, List *resultRelations)
{
        Index           rtsize = parentestate->es_range_table_size;

        /* initialize data not changing over EPQState's lifetime */
        epqstate->parentestate = parentestate;
        epqstate->epqParam = epqParam;
        epqstate->resultRelations = resultRelations;

        /*
         * Allocate space to reference a slot for each potential rti - do so now
         * rather than in EvalPlanQualBegin(), as done for other dynamically
         * allocated resources, so EvalPlanQualSlot() can be used to hold tuples
         * that *may* need EPQ later, without forcing the overhead of
         * EvalPlanQualBegin().
         */
        epqstate->tuple_table = NIL;
        epqstate->relsubs_slot = (TupleTableSlot **)
                palloc0(rtsize * sizeof(TupleTableSlot *));

        /* ... and remember data that EvalPlanQualBegin will need */
        epqstate->plan = subplan;
        epqstate->arowMarks = auxrowmarks;

        /* ... and mark the EPQ state inactive */
        epqstate->origslot = NULL;
        epqstate->recheckestate = NULL;
        epqstate->recheckplanstate = NULL;
        epqstate->relsubs_rowmark = NULL;
        epqstate->relsubs_done = NULL;
        epqstate->relsubs_blocked = NULL;
}

/*
 * EvalPlanQualSetPlan -- set or change subplan of an EPQState.
 *
 * We used to need this so that ModifyTable could deal with multiple subplans.
 * It could now be refactored out of existence.
 */
void
EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan, List *auxrowmarks)
{
        /* If we have a live EPQ query, shut it down */
        EvalPlanQualEnd(epqstate);
        /* And set/change the plan pointer */
        epqstate->plan = subplan;
        /* The rowmarks depend on the plan, too */
        epqstate->arowMarks = auxrowmarks;
}

/*
 * Return, and create if necessary, a slot for an EPQ test tuple.
 *
 * Note this only requires EvalPlanQualInit() to have been called,
 * EvalPlanQualBegin() is not necessary.
 */
TupleTableSlot *
EvalPlanQualSlot(EPQState *epqstate,
                                 Relation relation, Index rti)
{
        TupleTableSlot **slot;

        Assert(relation);
        Assert(rti > 0 && rti <= epqstate->parentestate->es_range_table_size);
        slot = &epqstate->relsubs_slot[rti - 1];

        if (*slot == NULL)
        {
                MemoryContext oldcontext;

                oldcontext = MemoryContextSwitchTo(epqstate->parentestate->es_query_cxt);
                *slot = table_slot_create(relation, &epqstate->tuple_table);
                MemoryContextSwitchTo(oldcontext);
        }

        return *slot;
}

/*
 * Fetch the current row value for a non-locked relation, identified by rti,
 * that needs to be scanned by an EvalPlanQual operation.  origslot must have
 * been set to contain the current result row (top-level row) that we need to
 * recheck.  Returns true if a substitution tuple was found, false if not.
 */
bool
EvalPlanQualFetchRowMark(EPQState *epqstate, Index rti, TupleTableSlot *slot)
{
        ExecAuxRowMark *earm = epqstate->relsubs_rowmark[rti - 1];
        ExecRowMark *erm = earm->rowmark;
        Datum           datum;
        bool            isNull;

        Assert(earm != NULL);
        Assert(epqstate->origslot != NULL);

        if (RowMarkRequiresRowShareLock(erm->markType))
                elog(ERROR, "EvalPlanQual doesn't support locking rowmarks");

        /* if child rel, must check whether it produced this row */
        if (erm->rti != erm->prti)
        {
                Oid                     tableoid;

                datum = ExecGetJunkAttribute(epqstate->origslot,
                                                                         earm->toidAttNo,
                                                                         &isNull);
                /* non-locked rels could be on the inside of outer joins */
                if (isNull)
                        return false;

                tableoid = DatumGetObjectId(datum);

                Assert(OidIsValid(erm->relid));
                if (tableoid != erm->relid)
                {
                        /* this child is inactive right now */
                        return false;
                }
        }

        if (erm->markType == ROW_MARK_REFERENCE)
        {
                Assert(erm->relation != NULL);

                /* fetch the tuple's ctid */
                datum = ExecGetJunkAttribute(epqstate->origslot,
                                                                         earm->ctidAttNo,
                                                                         &isNull);
                /* non-locked rels could be on the inside of outer joins */
                if (isNull)
                        return false;

                /* fetch requests on foreign tables must be passed to their FDW */
                if (erm->relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
                {
                        FdwRoutine *fdwroutine;
                        bool            updated = false;

                        fdwroutine = GetFdwRoutineForRelation(erm->relation, false);
                        /* this should have been checked already, but let's be safe */
                        if (fdwroutine->RefetchForeignRow == NULL)
                                ereport(ERROR,
                                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                                 errmsg("cannot lock rows in foreign table \"%s\"",
                                                                RelationGetRelationName(erm->relation))));

                        fdwroutine->RefetchForeignRow(epqstate->recheckestate,
                                                                                  erm,
                                                                                  datum,
                                                                                  slot,
                                                                                  &updated);
                        if (TupIsNull(slot))
                                elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");

                        /*
                         * Ideally we'd insist on updated == false here, but that assumes
                         * that FDWs can track that exactly, which they might not be able
                         * to.  So just ignore the flag.
                         */
                        return true;
                }
                else
                {
                        /* ordinary table, fetch the tuple */
                        if (!table_tuple_fetch_row_version(erm->relation,
                                                                                           (ItemPointer) DatumGetPointer(datum),
                                                                                           SnapshotAny, slot))
                                elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
                        return true;
                }
        }
        else
        {
                Assert(erm->markType == ROW_MARK_COPY);

                /* fetch the whole-row Var for the relation */
                datum = ExecGetJunkAttribute(epqstate->origslot,
                                                                         earm->wholeAttNo,
                                                                         &isNull);
                /* non-locked rels could be on the inside of outer joins */
                if (isNull)
                        return false;

                ExecStoreHeapTupleDatum(datum, slot);
                return true;
        }
}

/*
 * Fetch the next row (if any) from EvalPlanQual testing
 *
 * (In practice, there should never be more than one row...)
 */
TupleTableSlot *
EvalPlanQualNext(EPQState *epqstate)
{
        MemoryContext oldcontext;
        TupleTableSlot *slot;

        oldcontext = MemoryContextSwitchTo(epqstate->recheckestate->es_query_cxt);
        slot = ExecProcNode(epqstate->recheckplanstate);
        MemoryContextSwitchTo(oldcontext);

        return slot;
}

/*
 * Initialize or reset an EvalPlanQual state tree
 */
void
EvalPlanQualBegin(EPQState *epqstate)
{
        EState     *parentestate = epqstate->parentestate;
        EState     *recheckestate = epqstate->recheckestate;

        if (recheckestate == NULL)
        {
                /* First time through, so create a child EState */
                EvalPlanQualStart(epqstate, epqstate->plan);
        }
        else
        {
                /*
                 * We already have a suitable child EPQ tree, so just reset it.
                 */
                Index           rtsize = parentestate->es_range_table_size;
                PlanState  *rcplanstate = epqstate->recheckplanstate;

                /*
                 * Reset the relsubs_done[] flags to equal relsubs_blocked[], so that
                 * the EPQ run will never attempt to fetch tuples from blocked target
                 * relations.
                 */
                memcpy(epqstate->relsubs_done, epqstate->relsubs_blocked,
                           rtsize * sizeof(bool));

                /* Recopy current values of parent parameters */
                if (parentestate->es_plannedstmt->paramExecTypes != NIL)
                {
                        int                     i;

                        /*
                         * Force evaluation of any InitPlan outputs that could be needed
                         * by the subplan, just in case they got reset since
                         * EvalPlanQualStart (see comments therein).
                         */
                        ExecSetParamPlanMulti(rcplanstate->plan->extParam,
                                                                  GetPerTupleExprContext(parentestate));

                        i = list_length(parentestate->es_plannedstmt->paramExecTypes);

                        while (--i >= 0)
                        {
                                /* copy value if any, but not execPlan link */
                                recheckestate->es_param_exec_vals[i].value =
                                        parentestate->es_param_exec_vals[i].value;
                                recheckestate->es_param_exec_vals[i].isnull =
                                        parentestate->es_param_exec_vals[i].isnull;
                        }
                }

                /*
                 * Mark child plan tree as needing rescan at all scan nodes.  The
                 * first ExecProcNode will take care of actually doing the rescan.
                 */
                rcplanstate->chgParam = bms_add_member(rcplanstate->chgParam,
                                                                                           epqstate->epqParam);
        }
}

/*
 * Start execution of an EvalPlanQual plan tree.
 *
 * This is a cut-down version of ExecutorStart(): we copy some state from
 * the top-level estate rather than initializing it fresh.
 */
static void
EvalPlanQualStart(EPQState *epqstate, Plan *planTree)
{
        EState     *parentestate = epqstate->parentestate;
        Index           rtsize = parentestate->es_range_table_size;
        EState     *rcestate;
        MemoryContext oldcontext;
        ListCell   *l;

        epqstate->recheckestate = rcestate = CreateExecutorState();

        oldcontext = MemoryContextSwitchTo(rcestate->es_query_cxt);

        /* signal that this is an EState for executing EPQ */
        rcestate->es_epq_active = epqstate;

        /*
         * Child EPQ EStates share the parent's copy of unchanging state such as
         * the snapshot, rangetable, and external Param info.  They need their own
         * copies of local state, including a tuple table, es_param_exec_vals,
         * result-rel info, etc.
         */
        rcestate->es_direction = ForwardScanDirection;
        rcestate->es_snapshot = parentestate->es_snapshot;
        rcestate->es_crosscheck_snapshot = parentestate->es_crosscheck_snapshot;
        rcestate->es_range_table = parentestate->es_range_table;
        rcestate->es_range_table_size = parentestate->es_range_table_size;
        rcestate->es_relations = parentestate->es_relations;
        rcestate->es_rowmarks = parentestate->es_rowmarks;
        rcestate->es_rteperminfos = parentestate->es_rteperminfos;
        rcestate->es_plannedstmt = parentestate->es_plannedstmt;
        rcestate->es_junkFilter = parentestate->es_junkFilter;
        rcestate->es_output_cid = parentestate->es_output_cid;
        rcestate->es_queryEnv = parentestate->es_queryEnv;

        /*
         * ResultRelInfos needed by subplans are initialized from scratch when the
         * subplans themselves are initialized.
         */
        rcestate->es_result_relations = NULL;
        /* es_trig_target_relations must NOT be copied */
        rcestate->es_top_eflags = parentestate->es_top_eflags;
        rcestate->es_instrument = parentestate->es_instrument;
        /* es_auxmodifytables must NOT be copied */

        /*
         * The external param list is simply shared from parent.  The internal
         * param workspace has to be local state, but we copy the initial values
         * from the parent, so as to have access to any param values that were
         * already set from other parts of the parent's plan tree.
         */
        rcestate->es_param_list_info = parentestate->es_param_list_info;
        if (parentestate->es_plannedstmt->paramExecTypes != NIL)
        {
                int                     i;

                /*
                 * Force evaluation of any InitPlan outputs that could be needed by
                 * the subplan.  (With more complexity, maybe we could postpone this
                 * till the subplan actually demands them, but it doesn't seem worth
                 * the trouble; this is a corner case already, since usually the
                 * InitPlans would have been evaluated before reaching EvalPlanQual.)
                 *
                 * This will not touch output params of InitPlans that occur somewhere
                 * within the subplan tree, only those that are attached to the
                 * ModifyTable node or above it and are referenced within the subplan.
                 * That's OK though, because the planner would only attach such
                 * InitPlans to a lower-level SubqueryScan node, and EPQ execution
                 * will not descend into a SubqueryScan.
                 *
                 * The EState's per-output-tuple econtext is sufficiently short-lived
                 * for this, since it should get reset before there is any chance of
                 * doing EvalPlanQual again.
                 */
                ExecSetParamPlanMulti(planTree->extParam,
                                                          GetPerTupleExprContext(parentestate));

                /* now make the internal param workspace ... */
                i = list_length(parentestate->es_plannedstmt->paramExecTypes);
                rcestate->es_param_exec_vals = (ParamExecData *)
                        palloc0(i * sizeof(ParamExecData));
                /* ... and copy down all values, whether really needed or not */
                while (--i >= 0)
                {
                        /* copy value if any, but not execPlan link */
                        rcestate->es_param_exec_vals[i].value =
                                parentestate->es_param_exec_vals[i].value;
                        rcestate->es_param_exec_vals[i].isnull =
                                parentestate->es_param_exec_vals[i].isnull;
                }
        }

        /*
         * Initialize private state information for each SubPlan.  We must do this
         * before running ExecInitNode on the main query tree, since
         * ExecInitSubPlan expects to be able to find these entries. Some of the
         * SubPlans might not be used in the part of the plan tree we intend to
         * run, but since it's not easy to tell which, we just initialize them
         * all.
         */
        Assert(rcestate->es_subplanstates == NIL);
        foreach(l, parentestate->es_plannedstmt->subplans)
        {
                Plan       *subplan = (Plan *) lfirst(l);
                PlanState  *subplanstate;

                subplanstate = ExecInitNode(subplan, rcestate, 0);
                rcestate->es_subplanstates = lappend(rcestate->es_subplanstates,
                                                                                         subplanstate);
        }

        /*
         * Build an RTI indexed array of rowmarks, so that
         * EvalPlanQualFetchRowMark() can efficiently access the to be fetched
         * rowmark.
         */
        epqstate->relsubs_rowmark = (ExecAuxRowMark **)
                palloc0(rtsize * sizeof(ExecAuxRowMark *));
        foreach(l, epqstate->arowMarks)
        {
                ExecAuxRowMark *earm = (ExecAuxRowMark *) lfirst(l);

                epqstate->relsubs_rowmark[earm->rowmark->rti - 1] = earm;
        }

        /*
         * Initialize per-relation EPQ tuple states.  Result relations, if any,
         * get marked as blocked; others as not-fetched.
         */
        epqstate->relsubs_done = palloc_array(bool, rtsize);
        epqstate->relsubs_blocked = palloc0_array(bool, rtsize);

        foreach(l, epqstate->resultRelations)
        {
                int                     rtindex = lfirst_int(l);

                Assert(rtindex > 0 && rtindex <= rtsize);
                epqstate->relsubs_blocked[rtindex - 1] = true;
        }

        memcpy(epqstate->relsubs_done, epqstate->relsubs_blocked,
                   rtsize * sizeof(bool));

        /*
         * Initialize the private state information for all the nodes in the part
         * of the plan tree we need to run.  This opens files, allocates storage
         * and leaves us ready to start processing tuples.
         */
        epqstate->recheckplanstate = ExecInitNode(planTree, rcestate, 0);

        MemoryContextSwitchTo(oldcontext);
}

/*
 * EvalPlanQualEnd -- shut down at termination of parent plan state node,
 * or if we are done with the current EPQ child.
 *
 * This is a cut-down version of ExecutorEnd(); basically we want to do most
 * of the normal cleanup, but *not* close result relations (which we are
 * just sharing from the outer query).  We do, however, have to close any
 * result and trigger target relations that got opened, since those are not
 * shared.  (There probably shouldn't be any of the latter, but just in
 * case...)
 */
void
EvalPlanQualEnd(EPQState *epqstate)
{
        EState     *estate = epqstate->recheckestate;
        Index           rtsize;
        MemoryContext oldcontext;
        ListCell   *l;

        rtsize = epqstate->parentestate->es_range_table_size;

        /*
         * We may have a tuple table, even if EPQ wasn't started, because we allow
         * use of EvalPlanQualSlot() without calling EvalPlanQualBegin().
         */
        if (epqstate->tuple_table != NIL)
        {
                memset(epqstate->relsubs_slot, 0,
                           rtsize * sizeof(TupleTableSlot *));
                ExecResetTupleTable(epqstate->tuple_table, true);
                epqstate->tuple_table = NIL;
        }

        /* EPQ wasn't started, nothing further to do */
        if (estate == NULL)
                return;

        oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

        ExecEndNode(epqstate->recheckplanstate);

        foreach(l, estate->es_subplanstates)
        {
                PlanState  *subplanstate = (PlanState *) lfirst(l);

                ExecEndNode(subplanstate);
        }

        /* throw away the per-estate tuple table, some node may have used it */
        ExecResetTupleTable(estate->es_tupleTable, false);

        /* Close any result and trigger target relations attached to this EState */
        ExecCloseResultRelations(estate);

        MemoryContextSwitchTo(oldcontext);

        FreeExecutorState(estate);

        /* Mark EPQState idle */
        epqstate->origslot = NULL;
        epqstate->recheckestate = NULL;
        epqstate->recheckplanstate = NULL;
        epqstate->relsubs_rowmark = NULL;
        epqstate->relsubs_done = NULL;
        epqstate->relsubs_blocked = NULL;
}