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    d0b4399d
    Reimplement the linked list data structure used throughout the backend. · d0b4399d
    Neil Conway authored
    In the past, we used a 'Lispy' linked list implementation: a "list" was
    merely a pointer to the head node of the list. The problem with that
    design is that it makes lappend() and length() linear time. This patch
    fixes that problem (and others) by maintaining a count of the list
    length and a pointer to the tail node along with each head node pointer.
    A "list" is now a pointer to a structure containing some meta-data
    about the list; the head and tail pointers in that structure refer
    to ListCell structures that maintain the actual linked list of nodes.
    
    The function names of the list API have also been changed to, I hope,
    be more logically consistent. By default, the old function names are
    still available; they will be disabled-by-default once the rest of
    the tree has been updated to use the new API names.
    d0b4399d
    History
    Reimplement the linked list data structure used throughout the backend.
    Neil Conway authored
    In the past, we used a 'Lispy' linked list implementation: a "list" was
    merely a pointer to the head node of the list. The problem with that
    design is that it makes lappend() and length() linear time. This patch
    fixes that problem (and others) by maintaining a count of the list
    length and a pointer to the tail node along with each head node pointer.
    A "list" is now a pointer to a structure containing some meta-data
    about the list; the head and tail pointers in that structure refer
    to ListCell structures that maintain the actual linked list of nodes.
    
    The function names of the list API have also been changed to, I hope,
    be more logically consistent. By default, the old function names are
    still available; they will be disabled-by-default once the rest of
    the tree has been updated to use the new API names.
execUtils.c 26.66 KiB
/*-------------------------------------------------------------------------
 *
 * execUtils.c
 *	  miscellaneous executor utility routines
 *
 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.111 2004/05/26 04:41:15 neilc Exp $
 *
 *-------------------------------------------------------------------------
 */
/*
 * INTERFACE ROUTINES
 *		CreateExecutorState		Create/delete executor working state
 *		FreeExecutorState
 *		CreateExprContext
 *		FreeExprContext
 *		ReScanExprContext
 *
 *		ExecAssignExprContext	Common code for plan node init routines.
 *		ExecAssignResultType
 *		etc
 *
 *		ExecOpenIndices			\
 *		ExecCloseIndices		 | referenced by InitPlan, EndPlan,
 *		ExecInsertIndexTuples	/  ExecInsert, ExecUpdate
 *
 *		RegisterExprContextCallback    Register function shutdown callback
 *		UnregisterExprContextCallback  Deregister function shutdown callback
 *
 *	 NOTES
 *		This file has traditionally been the place to stick misc.
 *		executor support stuff that doesn't really go anyplace else.
 */

#include "postgres.h"

#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/index.h"
#include "catalog/catalog.h"
#include "catalog/pg_index.h"
#include "executor/execdebug.h"
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/memutils.h"
#include "utils/relcache.h"
#include "utils/syscache.h"


/* ----------------------------------------------------------------
 *		global counters for number of tuples processed, retrieved,
 *		appended, replaced, deleted.
 * ----------------------------------------------------------------
 */
int			NTupleProcessed;
int			NTupleRetrieved;
int			NTupleReplaced;
int			NTupleAppended;
int			NTupleDeleted;
int			NIndexTupleInserted;
extern int	NIndexTupleProcessed;		/* have to be defined in the
										 * access method level so that the
										 * cinterface.a will link ok. */

static void ShutdownExprContext(ExprContext *econtext);


/* ----------------------------------------------------------------
 *						statistic functions
 * ----------------------------------------------------------------
 */

/* ----------------------------------------------------------------
 *		ResetTupleCount
 * ----------------------------------------------------------------
 */
#ifdef NOT_USED
void
ResetTupleCount(void)
{
	NTupleProcessed = 0;
	NTupleRetrieved = 0;
	NTupleAppended = 0;
	NTupleDeleted = 0;
	NTupleReplaced = 0;
	NIndexTupleProcessed = 0;
}
#endif

/* ----------------------------------------------------------------
 *		PrintTupleCount
 * ----------------------------------------------------------------
 */
#ifdef NOT_USED
void
DisplayTupleCount(FILE *statfp)
{
	if (NTupleProcessed > 0)
		fprintf(statfp, "!\t%d tuple%s processed, ", NTupleProcessed,
				(NTupleProcessed == 1) ? "" : "s");
	else
	{
		fprintf(statfp, "!\tno tuples processed.\n");
		return;
	}
	if (NIndexTupleProcessed > 0)
		fprintf(statfp, "%d indextuple%s processed, ", NIndexTupleProcessed,
				(NIndexTupleProcessed == 1) ? "" : "s");
	if (NIndexTupleInserted > 0)
		fprintf(statfp, "%d indextuple%s inserted, ", NIndexTupleInserted,
				(NIndexTupleInserted == 1) ? "" : "s");
	if (NTupleRetrieved > 0)
		fprintf(statfp, "%d tuple%s retrieved. ", NTupleRetrieved,
				(NTupleRetrieved == 1) ? "" : "s");
	if (NTupleAppended > 0)
		fprintf(statfp, "%d tuple%s appended. ", NTupleAppended,
				(NTupleAppended == 1) ? "" : "s");
	if (NTupleDeleted > 0)
		fprintf(statfp, "%d tuple%s deleted. ", NTupleDeleted,
				(NTupleDeleted == 1) ? "" : "s");
	if (NTupleReplaced > 0)
		fprintf(statfp, "%d tuple%s replaced. ", NTupleReplaced,
				(NTupleReplaced == 1) ? "" : "s");
	fprintf(statfp, "\n");
}
#endif


/* ----------------------------------------------------------------
 *				 Executor state and memory management functions
 * ----------------------------------------------------------------
 */
/* ----------------
 *		CreateExecutorState
 *
 *		Create and initialize an EState node, which is the root of
 *		working storage for an entire Executor invocation.
 *
 * Principally, this creates the per-query memory context that will be
 * used to hold all working data that lives till the end of the query.
 * Note that the per-query context will become a child of the caller's
 * CurrentMemoryContext.
 * ----------------
 */
EState *
CreateExecutorState(void)
{
	EState	   *estate;
	MemoryContext qcontext;
	MemoryContext oldcontext;

	/*
	 * Create the per-query context for this Executor run.
	 */
	qcontext = AllocSetContextCreate(CurrentMemoryContext,
									 "ExecutorState",
									 ALLOCSET_DEFAULT_MINSIZE,
									 ALLOCSET_DEFAULT_INITSIZE,
									 ALLOCSET_DEFAULT_MAXSIZE);

	/*
	 * Make the EState node within the per-query context.  This way, we
	 * don't need a separate pfree() operation for it at shutdown.
	 */
	oldcontext = MemoryContextSwitchTo(qcontext);

	estate = makeNode(EState);

	/*
	 * Initialize all fields of the Executor State structure
	 */
	estate->es_direction = ForwardScanDirection;
	estate->es_snapshot = SnapshotNow;
	estate->es_crosscheck_snapshot = SnapshotAny; /* means no crosscheck */
	estate->es_range_table = NIL;

	estate->es_result_relations = NULL;
	estate->es_num_result_relations = 0;
	estate->es_result_relation_info = NULL;

	estate->es_junkFilter = NULL;
	estate->es_into_relation_descriptor = NULL;

	estate->es_param_list_info = NULL;
	estate->es_param_exec_vals = NULL;

	estate->es_query_cxt = qcontext;

	estate->es_tupleTable = NULL;

	estate->es_processed = 0;
	estate->es_lastoid = InvalidOid;
	estate->es_rowMark = NIL;

	estate->es_instrument = false;
	estate->es_select_into = false;
	estate->es_into_oids = false;

	estate->es_exprcontexts = NIL;

	estate->es_per_tuple_exprcontext = NULL;
	estate->es_topPlan = NULL;
	estate->es_evalPlanQual = NULL;
	estate->es_evTupleNull = NULL;
	estate->es_evTuple = NULL;
	estate->es_useEvalPlan = false;

	/*
	 * Return the executor state structure
	 */
	MemoryContextSwitchTo(oldcontext);

	return estate;
}

/* ----------------
 *		FreeExecutorState
 *
 *		Release an EState along with all remaining working storage.
 *
 * Note: this is not responsible for releasing non-memory resources,
 * such as open relations or buffer pins.  But it will shut down any
 * still-active ExprContexts within the EState.  That is sufficient
 * cleanup for situations where the EState has only been used for expression
 * evaluation, and not to run a complete Plan.
 *
 * This can be called in any memory context ... so long as it's not one
 * of the ones to be freed.
 * ----------------
 */
void
FreeExecutorState(EState *estate)
{
	/*
	 * Shut down and free any remaining ExprContexts.  We do this
	 * explicitly to ensure that any remaining shutdown callbacks get
	 * called (since they might need to release resources that aren't
	 * simply memory within the per-query memory context).
	 */
	while (estate->es_exprcontexts)
	{
		/* XXX: seems there ought to be a faster way to implement this
		 * than repeated lremove(), no?
		 */
		FreeExprContext((ExprContext *) linitial(estate->es_exprcontexts));
		/* FreeExprContext removed the list link for us */
	}

	/*
	 * Free the per-query memory context, thereby releasing all working
	 * memory, including the EState node itself.
	 */
	MemoryContextDelete(estate->es_query_cxt);
}

/* ----------------
 *		CreateExprContext
 *
 *		Create a context for expression evaluation within an EState.
 *
 * An executor run may require multiple ExprContexts (we usually make one
 * for each Plan node, and a separate one for per-output-tuple processing
 * such as constraint checking).  Each ExprContext has its own "per-tuple"
 * memory context.
 *
 * Note we make no assumption about the caller's memory context.
 * ----------------
 */
ExprContext *
CreateExprContext(EState *estate)
{
	ExprContext *econtext;
	MemoryContext oldcontext;

	/* Create the ExprContext node within the per-query memory context */
	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);

	econtext = makeNode(ExprContext);

	/* Initialize fields of ExprContext */
	econtext->ecxt_scantuple = NULL;
	econtext->ecxt_innertuple = NULL;
	econtext->ecxt_outertuple = NULL;

	econtext->ecxt_per_query_memory = estate->es_query_cxt;

	/*
	 * Create working memory for expression evaluation in this context.
	 */
	econtext->ecxt_per_tuple_memory =
		AllocSetContextCreate(estate->es_query_cxt,
							  "ExprContext",
							  ALLOCSET_DEFAULT_MINSIZE,
							  ALLOCSET_DEFAULT_INITSIZE,
							  ALLOCSET_DEFAULT_MAXSIZE);

	econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
	econtext->ecxt_param_list_info = estate->es_param_list_info;

	econtext->ecxt_aggvalues = NULL;
	econtext->ecxt_aggnulls = NULL;

	econtext->caseValue_datum = (Datum) 0;
	econtext->caseValue_isNull = true;

	econtext->domainValue_datum = (Datum) 0;
	econtext->domainValue_isNull = true;

	econtext->ecxt_estate = estate;

	econtext->ecxt_callbacks = NULL;

	/*
	 * Link the ExprContext into the EState to ensure it is shut down when
	 * the EState is freed.  Because we use lcons(), shutdowns will occur
	 * in reverse order of creation, which may not be essential but can't
	 * hurt.
	 */
	estate->es_exprcontexts = lcons(econtext, estate->es_exprcontexts);

	MemoryContextSwitchTo(oldcontext);

	return econtext;
}

/* ----------------
 *		FreeExprContext
 *
 *		Free an expression context, including calling any remaining
 *		shutdown callbacks.
 *
 * Since we free the temporary context used for expression evaluation,
 * any previously computed pass-by-reference expression result will go away!
 *
 * Note we make no assumption about the caller's memory context.
 * ----------------
 */
void
FreeExprContext(ExprContext *econtext)
{
	EState	   *estate;

	/* Call any registered callbacks */
	ShutdownExprContext(econtext);
	/* And clean up the memory used */
	MemoryContextDelete(econtext->ecxt_per_tuple_memory);
	/* Unlink self from owning EState */
	estate = econtext->ecxt_estate;
	estate->es_exprcontexts = lremove(econtext, estate->es_exprcontexts);
	/* And delete the ExprContext node */
	pfree(econtext);
}

/*
 * ReScanExprContext
 *
 *		Reset an expression context in preparation for a rescan of its
 *		plan node.  This requires calling any registered shutdown callbacks,
 *		since any partially complete set-returning-functions must be canceled.
 *
 * Note we make no assumption about the caller's memory context.
 */
void
ReScanExprContext(ExprContext *econtext)
{
	/* Call any registered callbacks */
	ShutdownExprContext(econtext);
	/* And clean up the memory used */
	MemoryContextReset(econtext->ecxt_per_tuple_memory);
}

/*
 * Build a per-output-tuple ExprContext for an EState.
 *
 * This is normally invoked via GetPerTupleExprContext() macro,
 * not directly.
 */
ExprContext *
MakePerTupleExprContext(EState *estate)
{
	if (estate->es_per_tuple_exprcontext == NULL)
		estate->es_per_tuple_exprcontext = CreateExprContext(estate);

	return estate->es_per_tuple_exprcontext;
}


/* ----------------------------------------------------------------
 *				 miscellaneous node-init support functions
 *
 * Note: all of these are expected to be called with CurrentMemoryContext
 * equal to the per-query memory context.
 * ----------------------------------------------------------------
 */

/* ----------------
 *		ExecAssignExprContext
 *
 *		This initializes the ps_ExprContext field.	It is only necessary
 *		to do this for nodes which use ExecQual or ExecProject
 *		because those routines require an econtext. Other nodes that
 *		don't have to evaluate expressions don't need to do this.
 * ----------------
 */
void
ExecAssignExprContext(EState *estate, PlanState *planstate)
{
	planstate->ps_ExprContext = CreateExprContext(estate);
}

/* ----------------
 *		ExecAssignResultType
 * ----------------
 */
void
ExecAssignResultType(PlanState *planstate,
					 TupleDesc tupDesc, bool shouldFree)
{
	TupleTableSlot *slot = planstate->ps_ResultTupleSlot;

	ExecSetSlotDescriptor(slot, tupDesc, shouldFree);
}

/* ----------------
 *		ExecAssignResultTypeFromOuterPlan
 * ----------------
 */
void
ExecAssignResultTypeFromOuterPlan(PlanState *planstate)
{
	PlanState  *outerPlan;
	TupleDesc	tupDesc;

	outerPlan = outerPlanState(planstate);
	tupDesc = ExecGetResultType(outerPlan);

	ExecAssignResultType(planstate, tupDesc, false);
}

/* ----------------
 *		ExecAssignResultTypeFromTL
 * ----------------
 */
void
ExecAssignResultTypeFromTL(PlanState *planstate)
{
	bool		hasoid;
	TupleDesc	tupDesc;

	if (ExecContextForcesOids(planstate, &hasoid))
	{
		/* context forces OID choice; hasoid is now set correctly */
	}
	else
	{
		/* given free choice, don't leave space for OIDs in result tuples */
		hasoid = false;
	}

	/*
	 * ExecTypeFromTL needs the parse-time representation of the tlist,
	 * not a list of ExprStates.  This is good because some plan nodes
	 * don't bother to set up planstate->targetlist ...
	 */
	tupDesc = ExecTypeFromTL(planstate->plan->targetlist, hasoid);
	ExecAssignResultType(planstate, tupDesc, true);
}

/* ----------------
 *		ExecGetResultType
 * ----------------
 */
TupleDesc
ExecGetResultType(PlanState *planstate)
{
	TupleTableSlot *slot = planstate->ps_ResultTupleSlot;

	return slot->ttc_tupleDescriptor;
}

/* ----------------
 *		ExecBuildProjectionInfo
 *
 * Build a ProjectionInfo node for evaluating the given tlist in the given
 * econtext, and storing the result into the tuple slot.  (Caller must have
 * ensured that tuple slot has a descriptor matching the tlist!)  Note that
 * the given tlist should be a list of ExprState nodes, not Expr nodes.
 * ----------------
 */
ProjectionInfo *
ExecBuildProjectionInfo(List *targetList,
						ExprContext *econtext,
						TupleTableSlot *slot)
{
	ProjectionInfo *projInfo = makeNode(ProjectionInfo);
	int			len;

	len = ExecTargetListLength(targetList);

	projInfo->pi_targetlist = targetList;
	projInfo->pi_exprContext = econtext;
	projInfo->pi_slot = slot;
	if (len > 0)
	{
		projInfo->pi_tupValues = (Datum *) palloc(len * sizeof(Datum));
		projInfo->pi_tupNulls = (char *) palloc(len * sizeof(char));
		projInfo->pi_itemIsDone = (ExprDoneCond *) palloc(len * sizeof(ExprDoneCond));
	}

	return projInfo;
}

/* ----------------
 *		ExecAssignProjectionInfo
 *
 * forms the projection information from the node's targetlist
 * ----------------
 */
void
ExecAssignProjectionInfo(PlanState *planstate)
{
	planstate->ps_ProjInfo =
		ExecBuildProjectionInfo(planstate->targetlist,
								planstate->ps_ExprContext,
								planstate->ps_ResultTupleSlot);
}


/* ----------------
 *		ExecFreeExprContext
 *
 * A plan node's ExprContext should be freed explicitly during ExecEndNode
 * because there may be shutdown callbacks to call.  (Other resources made
 * by the above routines, such as projection info, don't need to be freed
 * explicitly because they're just memory in the per-query memory context.)
 * ----------------
 */
void
ExecFreeExprContext(PlanState *planstate)
{
	ExprContext *econtext;

	/*
	 * get expression context.	if NULL then this node has none so we just
	 * return.
	 */
	econtext = planstate->ps_ExprContext;
	if (econtext == NULL)
		return;

	FreeExprContext(econtext);

	planstate->ps_ExprContext = NULL;
}

/* ----------------------------------------------------------------
 *		the following scan type support functions are for
 *		those nodes which are stubborn and return tuples in
 *		their Scan tuple slot instead of their Result tuple
 *		slot..	luck fur us, these nodes do not do projections
 *		so we don't have to worry about getting the ProjectionInfo
 *		right for them...  -cim 6/3/91
 * ----------------------------------------------------------------
 */

/* ----------------
 *		ExecGetScanType
 * ----------------
 */
TupleDesc
ExecGetScanType(ScanState *scanstate)
{
	TupleTableSlot *slot = scanstate->ss_ScanTupleSlot;

	return slot->ttc_tupleDescriptor;
}

/* ----------------
 *		ExecAssignScanType
 * ----------------
 */
void
ExecAssignScanType(ScanState *scanstate,
				   TupleDesc tupDesc, bool shouldFree)
{
	TupleTableSlot *slot = scanstate->ss_ScanTupleSlot;

	ExecSetSlotDescriptor(slot, tupDesc, shouldFree);
}

/* ----------------
 *		ExecAssignScanTypeFromOuterPlan
 * ----------------
 */
void
ExecAssignScanTypeFromOuterPlan(ScanState *scanstate)
{
	PlanState  *outerPlan;
	TupleDesc	tupDesc;

	outerPlan = outerPlanState(scanstate);
	tupDesc = ExecGetResultType(outerPlan);

	ExecAssignScanType(scanstate, tupDesc, false);
}


/* ----------------------------------------------------------------
 *				  ExecInsertIndexTuples support
 * ----------------------------------------------------------------
 */

/* ----------------------------------------------------------------
 *		ExecOpenIndices
 *
 *		Find the indices associated with a result relation, open them,
 *		and save information about them in the result ResultRelInfo.
 *
 *		At entry, caller has already opened and locked
 *		resultRelInfo->ri_RelationDesc.
 *
 *		This used to be horribly ugly code, and slow too because it
 *		did a sequential scan of pg_index.	Now we rely on the relcache
 *		to cache a list of the OIDs of the indices associated with any
 *		specific relation, and we use the pg_index syscache to get the
 *		entries we need from pg_index.
 * ----------------------------------------------------------------
 */
void
ExecOpenIndices(ResultRelInfo *resultRelInfo)
{
	Relation	resultRelation = resultRelInfo->ri_RelationDesc;
	List	   *indexoidlist;
	ListCell   *l;
	int			len,
				i;
	RelationPtr relationDescs;
	IndexInfo **indexInfoArray;

	resultRelInfo->ri_NumIndices = 0;

	/* fast path if no indexes */
	if (!RelationGetForm(resultRelation)->relhasindex)
		return;

	/*
	 * Get cached list of index OIDs
	 */
	indexoidlist = RelationGetIndexList(resultRelation);
	len = length(indexoidlist);
	if (len == 0)
		return;

	/*
	 * allocate space for result arrays
	 */
	relationDescs = (RelationPtr) palloc(len * sizeof(Relation));
	indexInfoArray = (IndexInfo **) palloc(len * sizeof(IndexInfo *));

	resultRelInfo->ri_NumIndices = len;
	resultRelInfo->ri_IndexRelationDescs = relationDescs;
	resultRelInfo->ri_IndexRelationInfo = indexInfoArray;

	/*
	 * For each index, open the index relation and save pg_index info.
	 */
	i = 0;
	foreach(l, indexoidlist)
	{
		Oid			indexOid = lfirsto(l);
		Relation	indexDesc;
		IndexInfo  *ii;

		/*
		 * Open (and lock, if necessary) the index relation
		 *
		 * If the index AM is not safe for concurrent updates, obtain an
		 * exclusive lock on the index to lock out other updaters as well
		 * as readers (index_beginscan places AccessShareLock). We will
		 * release this lock in ExecCloseIndices.
		 *
		 * If the index AM supports concurrent updates, we obtain no lock
		 * here at all, which is a tad weird, but safe since any critical
		 * operation on the index (like deleting it) will acquire
		 * exclusive lock on the parent table.	Perhaps someday we should
		 * acquire RowExclusiveLock on the index here?
		 *
		 * If there are multiple not-concurrent-safe indexes, all backends
		 * must lock the indexes in the same order or we will get
		 * deadlocks here during concurrent updates.  This is guaranteed
		 * by RelationGetIndexList(), which promises to return the index
		 * list in OID order.
		 */
		indexDesc = index_open(indexOid);

		if (!indexDesc->rd_am->amconcurrent)
			LockRelation(indexDesc, AccessExclusiveLock);

		/* extract index key information from the index's pg_index info */
		ii = BuildIndexInfo(indexDesc);

		relationDescs[i] = indexDesc;
		indexInfoArray[i] = ii;
		i++;
	}

	freeList(indexoidlist);
}

/* ----------------------------------------------------------------
 *		ExecCloseIndices
 *
 *		Close the index relations stored in resultRelInfo
 * ----------------------------------------------------------------
 */
void
ExecCloseIndices(ResultRelInfo *resultRelInfo)
{
	int			i;
	int			numIndices;
	RelationPtr indexDescs;

	numIndices = resultRelInfo->ri_NumIndices;
	indexDescs = resultRelInfo->ri_IndexRelationDescs;

	for (i = 0; i < numIndices; i++)
	{
		if (indexDescs[i] == NULL)
			continue;

		/* Drop lock, if one was acquired by ExecOpenIndices */
		if (!indexDescs[i]->rd_am->amconcurrent)
			UnlockRelation(indexDescs[i], AccessExclusiveLock);

		index_close(indexDescs[i]);
	}

	/*
	 * XXX should free indexInfo array here too?  Currently we assume that
	 * such stuff will be cleaned up automatically in FreeExecutorState.
	 */
}

/* ----------------------------------------------------------------
 *		ExecInsertIndexTuples
 *
 *		This routine takes care of inserting index tuples
 *		into all the relations indexing the result relation
 *		when a heap tuple is inserted into the result relation.
 *		Much of this code should be moved into the genam
 *		stuff as it only exists here because the genam stuff
 *		doesn't provide the functionality needed by the
 *		executor.. -cim 9/27/89
 * ----------------------------------------------------------------
 */
void
ExecInsertIndexTuples(TupleTableSlot *slot,
					  ItemPointer tupleid,
					  EState *estate,
					  bool is_vacuum)
{
	HeapTuple	heapTuple;
	ResultRelInfo *resultRelInfo;
	int			i;
	int			numIndices;
	RelationPtr relationDescs;
	Relation	heapRelation;
	TupleDesc	heapDescriptor;
	IndexInfo **indexInfoArray;
	ExprContext *econtext;
	Datum		datum[INDEX_MAX_KEYS];
	char		nullv[INDEX_MAX_KEYS];

	heapTuple = slot->val;

	/*
	 * Get information from the result relation info structure.
	 */
	resultRelInfo = estate->es_result_relation_info;
	numIndices = resultRelInfo->ri_NumIndices;
	relationDescs = resultRelInfo->ri_IndexRelationDescs;
	indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
	heapRelation = resultRelInfo->ri_RelationDesc;
	heapDescriptor = RelationGetDescr(heapRelation);

	/*
	 * We will use the EState's per-tuple context for evaluating
	 * predicates and index 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;

	/*
	 * for each index, form and insert the index tuple
	 */
	for (i = 0; i < numIndices; i++)
	{
		IndexInfo  *indexInfo;
		InsertIndexResult result;

		if (relationDescs[i] == NULL)
			continue;

		indexInfo = indexInfoArray[i];

		/* Check for partial index */
		if (indexInfo->ii_Predicate != NIL)
		{
			List	   *predicate;

			/*
			 * If predicate state not set up yet, create it (in the
			 * estate's per-query context)
			 */
			predicate = indexInfo->ii_PredicateState;
			if (predicate == NIL)
			{
				predicate = (List *)
					ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
									estate);
				indexInfo->ii_PredicateState = predicate;
			}

			/* Skip this index-update if the predicate isn't satisfied */
			if (!ExecQual(predicate, econtext, false))
				continue;
		}
		/*
		 * FormIndexDatum fills in its datum and null parameters with
		 * attribute information taken from the given heap tuple. It also
		 * computes any expressions needed.
		 */
		FormIndexDatum(indexInfo,
					   heapTuple,
					   heapDescriptor,
					   estate,
					   datum,
					   nullv);

		/*
		 * The index AM does the rest.	Note we suppress unique-index
		 * checks if we are being called from VACUUM, since VACUUM may
		 * need to move dead tuples that have the same keys as live ones.
		 */
		result = index_insert(relationDescs[i], /* index relation */
							  datum,	/* array of heaptuple Datums */
							  nullv,	/* info on nulls */
							  &(heapTuple->t_self),		/* tid of heap tuple */
							  heapRelation,
				  relationDescs[i]->rd_index->indisunique && !is_vacuum);

		/*
		 * keep track of index inserts for debugging
		 */
		IncrIndexInserted();

		if (result)
			pfree(result);
	}
}

/*
 * UpdateChangedParamSet
 *		Add changed parameters to a plan node's chgParam set
 */
void
UpdateChangedParamSet(PlanState *node, Bitmapset *newchg)
{
	Bitmapset  *parmset;

	/*
	 * The plan node only depends on params listed in its allParam set.
	 * Don't include anything else into its chgParam set.
	 */
	parmset = bms_intersect(node->plan->allParam, newchg);

	/*
	 * Keep node->chgParam == NULL if there's not actually any members;
	 * this allows the simplest possible tests in executor node files.
	 */
	if (!bms_is_empty(parmset))
		node->chgParam = bms_join(node->chgParam, parmset);
	else
		bms_free(parmset);
}

/*
 * Register a shutdown callback in an ExprContext.
 *
 * Shutdown callbacks will be called (in reverse order of registration)
 * when the ExprContext is deleted or rescanned.  This provides a hook
 * for functions called in the context to do any cleanup needed --- it's
 * particularly useful for functions returning sets.  Note that the
 * callback will *not* be called in the event that execution is aborted
 * by an error.
 */
void
RegisterExprContextCallback(ExprContext *econtext,
							ExprContextCallbackFunction function,
							Datum arg)
{
	ExprContext_CB *ecxt_callback;

	/* Save the info in appropriate memory context */
	ecxt_callback = (ExprContext_CB *)
		MemoryContextAlloc(econtext->ecxt_per_query_memory,
						   sizeof(ExprContext_CB));

	ecxt_callback->function = function;
	ecxt_callback->arg = arg;

	/* link to front of list for appropriate execution order */
	ecxt_callback->next = econtext->ecxt_callbacks;
	econtext->ecxt_callbacks = ecxt_callback;
}

/*
 * Deregister a shutdown callback in an ExprContext.
 *
 * Any list entries matching the function and arg will be removed.
 * This can be used if it's no longer necessary to call the callback.
 */
void
UnregisterExprContextCallback(ExprContext *econtext,
							  ExprContextCallbackFunction function,
							  Datum arg)
{
	ExprContext_CB **prev_callback;
	ExprContext_CB *ecxt_callback;

	prev_callback = &econtext->ecxt_callbacks;

	while ((ecxt_callback = *prev_callback) != NULL)
	{
		if (ecxt_callback->function == function && ecxt_callback->arg == arg)
		{
			*prev_callback = ecxt_callback->next;
			pfree(ecxt_callback);
		}
		else
			prev_callback = &ecxt_callback->next;
	}
}

/*
 * Call all the shutdown callbacks registered in an ExprContext.
 *
 * The callback list is emptied (important in case this is only a rescan
 * reset, and not deletion of the ExprContext).
 */
static void
ShutdownExprContext(ExprContext *econtext)
{
	ExprContext_CB *ecxt_callback;
	MemoryContext oldcontext;

	/* Fast path in normal case where there's nothing to do. */
	if (econtext->ecxt_callbacks == NULL)
		return;

	/*
	 * Call the callbacks in econtext's per-tuple context.  This ensures
	 * that any memory they might leak will get cleaned up.
	 */
	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);

	/*
	 * Call each callback function in reverse registration order.
	 */
	while ((ecxt_callback = econtext->ecxt_callbacks) != NULL)
	{
		econtext->ecxt_callbacks = ecxt_callback->next;
		(*ecxt_callback->function) (ecxt_callback->arg);
		pfree(ecxt_callback);
	}

	MemoryContextSwitchTo(oldcontext);
}