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6543d81d65
joins, and clean things up a good deal at the same time. Append plan node no longer hacks on rangetable at runtime --- instead, all child tables are given their own RT entries during planning. Concept of multiple target tables pushed up into execMain, replacing bug-prone implementation within nodeAppend. Planner now supports generating Append plans for inheritance sets either at the top of the plan (the old way) or at the bottom. Expanding at the bottom is appropriate for tables used as sources, since they may appear inside an outer join; but we must still expand at the top when the target of an UPDATE or DELETE is an inheritance set, because we actually need a different targetlist and junkfilter for each target table in that case. Fortunately a target table can't be inside an outer join... Bizarre mutual recursion between union_planner and prepunion.c is gone --- in fact, union_planner doesn't really have much to do with union queries anymore, so I renamed it grouping_planner.
1881 lines
47 KiB
C
1881 lines
47 KiB
C
/*-------------------------------------------------------------------------
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*
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* execMain.c
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* top level executor interface routines
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*
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* INTERFACE ROUTINES
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* ExecutorStart()
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* ExecutorRun()
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* ExecutorEnd()
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*
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* The old ExecutorMain() has been replaced by ExecutorStart(),
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* ExecutorRun() and ExecutorEnd()
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*
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* These three procedures are the external interfaces to the executor.
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* In each case, the query descriptor and the execution state is required
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* as arguments
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*
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* ExecutorStart() must be called at the beginning of any execution of any
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* query plan and ExecutorEnd() should always be called at the end of
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* execution of a plan.
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*
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* ExecutorRun accepts 'feature' and 'count' arguments that specify whether
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* the plan is to be executed forwards, backwards, and for how many tuples.
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*
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* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.132 2000/11/12 00:36:57 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/heapam.h"
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#include "catalog/heap.h"
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#include "commands/command.h"
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#include "commands/trigger.h"
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#include "executor/execdebug.h"
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#include "executor/execdefs.h"
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#include "miscadmin.h"
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#include "optimizer/var.h"
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#include "parser/parsetree.h"
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#include "utils/acl.h"
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/* decls for local routines only used within this module */
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static TupleDesc InitPlan(CmdType operation,
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Query *parseTree,
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Plan *plan,
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EState *estate);
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static void initResultRelInfo(ResultRelInfo *resultRelInfo,
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Index resultRelationIndex,
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List *rangeTable,
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CmdType operation);
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static void EndPlan(Plan *plan, EState *estate);
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static TupleTableSlot *ExecutePlan(EState *estate, Plan *plan,
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CmdType operation,
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long numberTuples,
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ScanDirection direction,
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DestReceiver *destfunc);
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static void ExecRetrieve(TupleTableSlot *slot,
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DestReceiver *destfunc,
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EState *estate);
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static void ExecAppend(TupleTableSlot *slot, ItemPointer tupleid,
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EState *estate);
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static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
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EState *estate);
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static void ExecReplace(TupleTableSlot *slot, ItemPointer tupleid,
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EState *estate);
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static TupleTableSlot *EvalPlanQualNext(EState *estate);
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static void EndEvalPlanQual(EState *estate);
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static void ExecCheckQueryPerms(CmdType operation, Query *parseTree,
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Plan *plan);
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static void ExecCheckPlanPerms(Plan *plan, List *rangeTable,
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CmdType operation);
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static void ExecCheckRTPerms(List *rangeTable, CmdType operation);
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static void ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation);
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/* end of local decls */
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/* ----------------------------------------------------------------
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* ExecutorStart
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*
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* This routine must be called at the beginning of any execution of any
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* query plan
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*
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* returns a TupleDesc which describes the attributes of the tuples to
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* be returned by the query.
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*
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* NB: the CurrentMemoryContext when this is called must be the context
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* to be used as the per-query context for the query plan. ExecutorRun()
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* and ExecutorEnd() must be called in this same memory context.
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* ----------------------------------------------------------------
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*/
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TupleDesc
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ExecutorStart(QueryDesc *queryDesc, EState *estate)
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{
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TupleDesc result;
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/* sanity checks */
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Assert(queryDesc != NULL);
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if (queryDesc->plantree->nParamExec > 0)
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{
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estate->es_param_exec_vals = (ParamExecData *)
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palloc(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
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MemSet(estate->es_param_exec_vals, 0,
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queryDesc->plantree->nParamExec * sizeof(ParamExecData));
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}
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/*
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* Make our own private copy of the current queries snapshot data
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*/
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if (QuerySnapshot == NULL)
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estate->es_snapshot = NULL;
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else
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{
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estate->es_snapshot = (Snapshot) palloc(sizeof(SnapshotData));
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memcpy(estate->es_snapshot, QuerySnapshot, sizeof(SnapshotData));
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if (estate->es_snapshot->xcnt > 0)
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{
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estate->es_snapshot->xip = (TransactionId *)
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palloc(estate->es_snapshot->xcnt * sizeof(TransactionId));
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memcpy(estate->es_snapshot->xip, QuerySnapshot->xip,
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estate->es_snapshot->xcnt * sizeof(TransactionId));
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}
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}
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/*
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* Initialize the plan
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*/
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result = InitPlan(queryDesc->operation,
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queryDesc->parsetree,
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queryDesc->plantree,
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estate);
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return result;
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}
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/* ----------------------------------------------------------------
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* ExecutorRun
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*
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* This is the main routine of the executor module. It accepts
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* the query descriptor from the traffic cop and executes the
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* query plan.
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*
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* ExecutorStart must have been called already.
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*
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* the different features supported are:
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* EXEC_RUN: retrieve all tuples in the forward direction
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* EXEC_FOR: retrieve 'count' number of tuples in the forward dir
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* EXEC_BACK: retrieve 'count' number of tuples in the backward dir
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* EXEC_RETONE: return one tuple but don't 'retrieve' it
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* used in postquel function processing
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*
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* Note: count = 0 is interpreted as "no limit".
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*
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* ----------------------------------------------------------------
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*/
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TupleTableSlot *
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ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, long count)
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{
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CmdType operation;
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Plan *plan;
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TupleTableSlot *result;
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CommandDest dest;
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DestReceiver *destfunc;
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/*
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* sanity checks
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*/
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Assert(queryDesc != NULL);
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/*
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* extract information from the query descriptor and the query
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* feature.
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*/
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operation = queryDesc->operation;
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plan = queryDesc->plantree;
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dest = queryDesc->dest;
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destfunc = DestToFunction(dest);
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estate->es_processed = 0;
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estate->es_lastoid = InvalidOid;
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/*
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* FIXME: the dest setup function ought to be handed the tuple desc
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* for the tuples to be output, but I'm not quite sure how to get that
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* info at this point. For now, passing NULL is OK because no
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* existing dest setup function actually uses the pointer.
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*/
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(*destfunc->setup) (destfunc, (TupleDesc) NULL);
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switch (feature)
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{
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case EXEC_RUN:
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result = ExecutePlan(estate,
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plan,
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operation,
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count,
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ForwardScanDirection,
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destfunc);
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break;
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case EXEC_FOR:
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result = ExecutePlan(estate,
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plan,
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operation,
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count,
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ForwardScanDirection,
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destfunc);
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break;
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/*
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* retrieve next n "backward" tuples
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*/
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case EXEC_BACK:
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result = ExecutePlan(estate,
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plan,
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operation,
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count,
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BackwardScanDirection,
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destfunc);
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break;
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/*
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* return one tuple but don't "retrieve" it. (this is used by
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* the rule manager..) -cim 9/14/89
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*/
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case EXEC_RETONE:
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result = ExecutePlan(estate,
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plan,
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operation,
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ONE_TUPLE,
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ForwardScanDirection,
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destfunc);
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break;
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default:
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elog(DEBUG, "ExecutorRun: Unknown feature %d", feature);
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result = NULL;
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break;
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}
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(*destfunc->cleanup) (destfunc);
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return result;
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}
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/* ----------------------------------------------------------------
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* ExecutorEnd
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*
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* This routine must be called at the end of any execution of any
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* query plan
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*
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* returns (AttrInfo*) which describes the attributes of the tuples to
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* be returned by the query.
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*
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* ----------------------------------------------------------------
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*/
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void
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ExecutorEnd(QueryDesc *queryDesc, EState *estate)
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{
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/* sanity checks */
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Assert(queryDesc != NULL);
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EndPlan(queryDesc->plantree, estate);
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/* XXX - clean up some more from ExecutorStart() - er1p */
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if (NULL == estate->es_snapshot)
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{
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/* nothing to free */
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}
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else
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{
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if (estate->es_snapshot->xcnt > 0)
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pfree(estate->es_snapshot->xip);
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pfree(estate->es_snapshot);
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}
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if (NULL == estate->es_param_exec_vals)
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{
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/* nothing to free */
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}
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else
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{
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pfree(estate->es_param_exec_vals);
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estate->es_param_exec_vals = NULL;
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}
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}
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/*
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* ExecCheckQueryPerms
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* Check access permissions for all relations referenced in a query.
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*/
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static void
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ExecCheckQueryPerms(CmdType operation, Query *parseTree, Plan *plan)
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{
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/*
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* Check RTEs in the query's primary rangetable.
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*/
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ExecCheckRTPerms(parseTree->rtable, operation);
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/*
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* Search for subplans and APPEND nodes to check their rangetables.
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*/
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ExecCheckPlanPerms(plan, parseTree->rtable, operation);
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}
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/*
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* ExecCheckPlanPerms
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* Recursively scan the plan tree to check access permissions in
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* subplans.
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*/
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static void
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ExecCheckPlanPerms(Plan *plan, List *rangeTable, CmdType operation)
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{
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List *subp;
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if (plan == NULL)
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return;
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/* Check subplans, which we assume are plain SELECT queries */
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foreach(subp, plan->initPlan)
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{
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SubPlan *subplan = (SubPlan *) lfirst(subp);
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ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
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ExecCheckPlanPerms(subplan->plan, subplan->rtable, CMD_SELECT);
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}
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foreach(subp, plan->subPlan)
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{
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SubPlan *subplan = (SubPlan *) lfirst(subp);
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ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
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ExecCheckPlanPerms(subplan->plan, subplan->rtable, CMD_SELECT);
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}
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/* Check lower plan nodes */
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ExecCheckPlanPerms(plan->lefttree, rangeTable, operation);
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ExecCheckPlanPerms(plan->righttree, rangeTable, operation);
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/* Do node-type-specific checks */
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switch (nodeTag(plan))
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{
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case T_SubqueryScan:
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{
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SubqueryScan *scan = (SubqueryScan *) plan;
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RangeTblEntry *rte;
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/* Recursively check the subquery */
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rte = rt_fetch(scan->scan.scanrelid, rangeTable);
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Assert(rte->subquery != NULL);
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ExecCheckQueryPerms(operation, rte->subquery, scan->subplan);
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break;
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}
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case T_Append:
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{
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Append *app = (Append *) plan;
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List *appendplans;
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foreach(appendplans, app->appendplans)
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{
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ExecCheckPlanPerms((Plan *) lfirst(appendplans),
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rangeTable,
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operation);
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}
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break;
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}
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default:
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break;
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}
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}
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|
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/*
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* ExecCheckRTPerms
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* Check access permissions for all relations listed in a range table.
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*/
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static void
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ExecCheckRTPerms(List *rangeTable, CmdType operation)
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{
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List *lp;
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foreach(lp, rangeTable)
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{
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RangeTblEntry *rte = lfirst(lp);
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ExecCheckRTEPerms(rte, operation);
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}
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}
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/*
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* ExecCheckRTEPerms
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* Check access permissions for a single RTE.
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*/
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static void
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ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation)
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{
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char *relName;
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Oid userid;
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int32 aclcheck_result;
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/*
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* If it's a subquery RTE, ignore it --- it will be checked when
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* ExecCheckPlanPerms finds the SubqueryScan node for it.
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*/
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if (rte->subquery)
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return;
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relName = rte->relname;
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|
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/*
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* userid to check as: current user unless we have a setuid indication.
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*
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* Note: GetUserId() is presently fast enough that there's no harm
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* in calling it separately for each RTE. If that stops being true,
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* we could call it once in ExecCheckQueryPerms and pass the userid
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* down from there. But for now, no need for the extra clutter.
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*/
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userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
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#define CHECK(MODE) pg_aclcheck(relName, userid, MODE)
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if (rte->checkForRead)
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{
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aclcheck_result = CHECK(ACL_RD);
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if (aclcheck_result != ACLCHECK_OK)
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elog(ERROR, "%s: %s",
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relName, aclcheck_error_strings[aclcheck_result]);
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}
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|
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if (rte->checkForWrite)
|
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{
|
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/*
|
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* Note: write access in a SELECT context means SELECT FOR UPDATE.
|
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* Right now we don't distinguish that from true update as far as
|
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* permissions checks are concerned.
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*/
|
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switch (operation)
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{
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case CMD_INSERT:
|
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/* Accept either APPEND or WRITE access for this */
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aclcheck_result = CHECK(ACL_AP);
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if (aclcheck_result != ACLCHECK_OK)
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aclcheck_result = CHECK(ACL_WR);
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break;
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case CMD_SELECT:
|
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case CMD_DELETE:
|
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case CMD_UPDATE:
|
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aclcheck_result = CHECK(ACL_WR);
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break;
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|
default:
|
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elog(ERROR, "ExecCheckRTEPerms: bogus operation %d",
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operation);
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aclcheck_result = ACLCHECK_OK; /* keep compiler quiet */
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break;
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}
|
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if (aclcheck_result != ACLCHECK_OK)
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elog(ERROR, "%s: %s",
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relName, aclcheck_error_strings[aclcheck_result]);
|
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}
|
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}
|
|
|
|
|
|
/* ===============================================================
|
|
* ===============================================================
|
|
static routines follow
|
|
* ===============================================================
|
|
* ===============================================================
|
|
*/
|
|
|
|
typedef struct execRowMark
|
|
{
|
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Relation relation;
|
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Index rti;
|
|
char resname[32];
|
|
} execRowMark;
|
|
|
|
typedef struct evalPlanQual
|
|
{
|
|
Plan *plan;
|
|
Index rti;
|
|
EState estate;
|
|
struct evalPlanQual *free;
|
|
} evalPlanQual;
|
|
|
|
/* ----------------------------------------------------------------
|
|
* InitPlan
|
|
*
|
|
* Initializes the query plan: open files, allocate storage
|
|
* and start up the rule manager
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static TupleDesc
|
|
InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
|
|
{
|
|
List *rangeTable;
|
|
Relation intoRelationDesc;
|
|
TupleDesc tupType;
|
|
|
|
/*
|
|
* Do permissions checks.
|
|
*/
|
|
ExecCheckQueryPerms(operation, parseTree, plan);
|
|
|
|
/*
|
|
* get information from query descriptor
|
|
*/
|
|
rangeTable = parseTree->rtable;
|
|
|
|
/*
|
|
* initialize the node's execution state
|
|
*/
|
|
estate->es_range_table = rangeTable;
|
|
|
|
/*
|
|
* if there is a result relation, initialize result relation stuff
|
|
*/
|
|
if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
|
|
{
|
|
List *resultRelations = parseTree->resultRelations;
|
|
int numResultRelations;
|
|
ResultRelInfo *resultRelInfos;
|
|
|
|
if (resultRelations != NIL)
|
|
{
|
|
/*
|
|
* Multiple result relations (due to inheritance)
|
|
* parseTree->resultRelations identifies them all
|
|
*/
|
|
ResultRelInfo *resultRelInfo;
|
|
|
|
numResultRelations = length(resultRelations);
|
|
resultRelInfos = (ResultRelInfo *)
|
|
palloc(numResultRelations * sizeof(ResultRelInfo));
|
|
resultRelInfo = resultRelInfos;
|
|
while (resultRelations != NIL)
|
|
{
|
|
initResultRelInfo(resultRelInfo,
|
|
lfirsti(resultRelations),
|
|
rangeTable,
|
|
operation);
|
|
resultRelInfo++;
|
|
resultRelations = lnext(resultRelations);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Single result relation identified by parseTree->resultRelation
|
|
*/
|
|
numResultRelations = 1;
|
|
resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
|
|
initResultRelInfo(resultRelInfos,
|
|
parseTree->resultRelation,
|
|
rangeTable,
|
|
operation);
|
|
}
|
|
|
|
estate->es_result_relations = resultRelInfos;
|
|
estate->es_num_result_relations = numResultRelations;
|
|
/* Initialize to first or only result rel */
|
|
estate->es_result_relation_info = resultRelInfos;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* if no result relation, then set state appropriately
|
|
*/
|
|
estate->es_result_relations = NULL;
|
|
estate->es_num_result_relations = 0;
|
|
estate->es_result_relation_info = NULL;
|
|
}
|
|
|
|
/*
|
|
* Have to lock relations selected for update
|
|
*/
|
|
estate->es_rowMark = NIL;
|
|
if (parseTree->rowMarks != NIL)
|
|
{
|
|
List *l;
|
|
|
|
foreach(l, parseTree->rowMarks)
|
|
{
|
|
Index rti = lfirsti(l);
|
|
Oid relid = getrelid(rti, rangeTable);
|
|
Relation relation;
|
|
execRowMark *erm;
|
|
|
|
relation = heap_open(relid, RowShareLock);
|
|
erm = (execRowMark *) palloc(sizeof(execRowMark));
|
|
erm->relation = relation;
|
|
erm->rti = rti;
|
|
sprintf(erm->resname, "ctid%u", rti);
|
|
estate->es_rowMark = lappend(estate->es_rowMark, erm);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* initialize the executor "tuple" table.
|
|
*/
|
|
{
|
|
int nSlots = ExecCountSlotsNode(plan);
|
|
TupleTable tupleTable = ExecCreateTupleTable(nSlots + 10); /* why add ten? - jolly */
|
|
|
|
estate->es_tupleTable = tupleTable;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ExecInitNode(plan, estate, NULL);
|
|
|
|
/*
|
|
* Get the tuple descriptor describing the type of tuples to return.
|
|
* (this is especially important if we are creating a relation with
|
|
* "retrieve into")
|
|
*/
|
|
tupType = ExecGetTupType(plan); /* tuple descriptor */
|
|
|
|
/*
|
|
* Initialize the junk filter if needed. SELECT and INSERT queries need
|
|
* a filter if there are any junk attrs in the tlist. UPDATE and
|
|
* DELETE always need one, since there's always a junk 'ctid' attribute
|
|
* present --- no need to look first.
|
|
*/
|
|
{
|
|
bool junk_filter_needed = false;
|
|
List *tlist;
|
|
|
|
switch (operation)
|
|
{
|
|
case CMD_SELECT:
|
|
case CMD_INSERT:
|
|
foreach(tlist, plan->targetlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tlist);
|
|
|
|
if (tle->resdom->resjunk)
|
|
{
|
|
junk_filter_needed = true;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
case CMD_UPDATE:
|
|
case CMD_DELETE:
|
|
junk_filter_needed = true;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (junk_filter_needed)
|
|
{
|
|
/*
|
|
* If there are multiple result relations, each one needs
|
|
* its own junk filter. Note this is only possible for
|
|
* UPDATE/DELETE, so we can't be fooled by some needing
|
|
* a filter and some not.
|
|
*/
|
|
if (parseTree->resultRelations != NIL)
|
|
{
|
|
List *subplans;
|
|
ResultRelInfo *resultRelInfo;
|
|
|
|
/* Top plan had better be an Append here. */
|
|
Assert(IsA(plan, Append));
|
|
Assert(((Append *) plan)->isTarget);
|
|
subplans = ((Append *) plan)->appendplans;
|
|
Assert(length(subplans) == estate->es_num_result_relations);
|
|
resultRelInfo = estate->es_result_relations;
|
|
while (subplans != NIL)
|
|
{
|
|
Plan *subplan = (Plan *) lfirst(subplans);
|
|
JunkFilter *j;
|
|
|
|
j = ExecInitJunkFilter(subplan->targetlist,
|
|
ExecGetTupType(subplan));
|
|
resultRelInfo->ri_junkFilter = j;
|
|
resultRelInfo++;
|
|
subplans = lnext(subplans);
|
|
}
|
|
/*
|
|
* Set active junkfilter too; at this point ExecInitAppend
|
|
* has already selected an active result relation...
|
|
*/
|
|
estate->es_junkFilter =
|
|
estate->es_result_relation_info->ri_junkFilter;
|
|
}
|
|
else
|
|
{
|
|
/* Normal case with just one JunkFilter */
|
|
JunkFilter *j = ExecInitJunkFilter(plan->targetlist,
|
|
tupType);
|
|
|
|
estate->es_junkFilter = j;
|
|
if (estate->es_result_relation_info)
|
|
estate->es_result_relation_info->ri_junkFilter = j;
|
|
|
|
/* For SELECT, want to return the cleaned tuple type */
|
|
if (operation == CMD_SELECT)
|
|
tupType = j->jf_cleanTupType;
|
|
}
|
|
}
|
|
else
|
|
estate->es_junkFilter = NULL;
|
|
}
|
|
|
|
/*
|
|
* initialize the "into" relation
|
|
*/
|
|
intoRelationDesc = (Relation) NULL;
|
|
|
|
if (operation == CMD_SELECT)
|
|
{
|
|
char *intoName;
|
|
Oid intoRelationId;
|
|
TupleDesc tupdesc;
|
|
|
|
if (!parseTree->isPortal)
|
|
{
|
|
|
|
/*
|
|
* a select into table
|
|
*/
|
|
if (parseTree->into != NULL)
|
|
{
|
|
|
|
/*
|
|
* create the "into" relation
|
|
*/
|
|
intoName = parseTree->into;
|
|
|
|
/*
|
|
* have to copy tupType to get rid of constraints
|
|
*/
|
|
tupdesc = CreateTupleDescCopy(tupType);
|
|
|
|
intoRelationId =
|
|
heap_create_with_catalog(intoName,
|
|
tupdesc,
|
|
RELKIND_RELATION,
|
|
parseTree->isTemp,
|
|
allowSystemTableMods);
|
|
|
|
FreeTupleDesc(tupdesc);
|
|
|
|
/*
|
|
* Advance command counter so that the newly-created
|
|
* relation's catalog tuples will be visible to heap_open.
|
|
*/
|
|
CommandCounterIncrement();
|
|
|
|
/*
|
|
* Eventually create a TOAST table for the into relation
|
|
*/
|
|
AlterTableCreateToastTable(intoName, true);
|
|
|
|
intoRelationDesc = heap_open(intoRelationId,
|
|
AccessExclusiveLock);
|
|
}
|
|
}
|
|
}
|
|
|
|
estate->es_into_relation_descriptor = intoRelationDesc;
|
|
|
|
estate->es_origPlan = plan;
|
|
estate->es_evalPlanQual = NULL;
|
|
estate->es_evTuple = NULL;
|
|
estate->es_useEvalPlan = false;
|
|
|
|
return tupType;
|
|
}
|
|
|
|
/*
|
|
* Initialize ResultRelInfo data for one result relation
|
|
*/
|
|
static void
|
|
initResultRelInfo(ResultRelInfo *resultRelInfo,
|
|
Index resultRelationIndex,
|
|
List *rangeTable,
|
|
CmdType operation)
|
|
{
|
|
Oid resultRelationOid;
|
|
Relation resultRelationDesc;
|
|
|
|
resultRelationOid = getrelid(resultRelationIndex, rangeTable);
|
|
resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
|
|
|
|
switch (resultRelationDesc->rd_rel->relkind)
|
|
{
|
|
case RELKIND_SEQUENCE:
|
|
elog(ERROR, "You can't change sequence relation %s",
|
|
RelationGetRelationName(resultRelationDesc));
|
|
break;
|
|
case RELKIND_TOASTVALUE:
|
|
elog(ERROR, "You can't change toast relation %s",
|
|
RelationGetRelationName(resultRelationDesc));
|
|
break;
|
|
case RELKIND_VIEW:
|
|
elog(ERROR, "You can't change view relation %s",
|
|
RelationGetRelationName(resultRelationDesc));
|
|
break;
|
|
}
|
|
|
|
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_ConstraintExprs = NULL;
|
|
resultRelInfo->ri_junkFilter = NULL;
|
|
|
|
/*
|
|
* If there are indices on the result relation, open them and save
|
|
* descriptors in the result relation info, so that we can add new
|
|
* index entries for the tuples we add/update. We need not do
|
|
* this for a DELETE, however, since deletion doesn't affect
|
|
* indexes.
|
|
*/
|
|
if (resultRelationDesc->rd_rel->relhasindex &&
|
|
operation != CMD_DELETE)
|
|
ExecOpenIndices(resultRelInfo);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* EndPlan
|
|
*
|
|
* Cleans up the query plan -- closes files and free up storages
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
EndPlan(Plan *plan, EState *estate)
|
|
{
|
|
ResultRelInfo *resultRelInfo;
|
|
int i;
|
|
List *l;
|
|
|
|
/*
|
|
* shut down any PlanQual processing we were doing
|
|
*/
|
|
if (estate->es_evalPlanQual != NULL)
|
|
EndEvalPlanQual(estate);
|
|
|
|
/*
|
|
* shut down the node-type-specific query processing
|
|
*/
|
|
ExecEndNode(plan, plan);
|
|
|
|
/*
|
|
* destroy the executor "tuple" table.
|
|
*/
|
|
ExecDropTupleTable(estate->es_tupleTable, true);
|
|
estate->es_tupleTable = NULL;
|
|
|
|
/*
|
|
* close the result relation(s) if any, but hold locks
|
|
* until xact commit.
|
|
*/
|
|
resultRelInfo = estate->es_result_relations;
|
|
for (i = estate->es_num_result_relations; i > 0; i--)
|
|
{
|
|
/* Close indices and then the relation itself */
|
|
ExecCloseIndices(resultRelInfo);
|
|
heap_close(resultRelInfo->ri_RelationDesc, NoLock);
|
|
resultRelInfo++;
|
|
}
|
|
|
|
/*
|
|
* close the "into" relation if necessary, again keeping lock
|
|
*/
|
|
if (estate->es_into_relation_descriptor != NULL)
|
|
heap_close(estate->es_into_relation_descriptor, NoLock);
|
|
|
|
/*
|
|
* close any relations selected FOR UPDATE, again keeping locks
|
|
*/
|
|
foreach(l, estate->es_rowMark)
|
|
{
|
|
execRowMark *erm = lfirst(l);
|
|
|
|
heap_close(erm->relation, NoLock);
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecutePlan
|
|
*
|
|
* processes the query plan to retrieve 'numberTuples' tuples in the
|
|
* direction specified.
|
|
* Retrieves all tuples if tupleCount is 0
|
|
*
|
|
* result is either a slot containing the last tuple in the case
|
|
* of a RETRIEVE or NULL otherwise.
|
|
*
|
|
* Note: the ctid attribute is a 'junk' attribute that is removed before the
|
|
* user can see it
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static TupleTableSlot *
|
|
ExecutePlan(EState *estate,
|
|
Plan *plan,
|
|
CmdType operation,
|
|
long numberTuples,
|
|
ScanDirection direction,
|
|
DestReceiver *destfunc)
|
|
{
|
|
JunkFilter *junkfilter;
|
|
TupleTableSlot *slot;
|
|
ItemPointer tupleid = NULL;
|
|
ItemPointerData tuple_ctid;
|
|
long current_tuple_count;
|
|
TupleTableSlot *result;
|
|
|
|
/*
|
|
* initialize local variables
|
|
*/
|
|
slot = NULL;
|
|
current_tuple_count = 0;
|
|
result = NULL;
|
|
|
|
/*
|
|
* Set the direction.
|
|
*/
|
|
estate->es_direction = direction;
|
|
|
|
/*
|
|
* Loop until we've processed the proper number of tuples from the
|
|
* plan..
|
|
*/
|
|
|
|
for (;;)
|
|
{
|
|
|
|
/*
|
|
* Execute the plan and obtain a tuple
|
|
*/
|
|
/* at the top level, the parent of a plan (2nd arg) is itself */
|
|
lnext: ;
|
|
if (estate->es_useEvalPlan)
|
|
{
|
|
slot = EvalPlanQualNext(estate);
|
|
if (TupIsNull(slot))
|
|
slot = ExecProcNode(plan, plan);
|
|
}
|
|
else
|
|
slot = ExecProcNode(plan, plan);
|
|
|
|
/*
|
|
* if the tuple is null, then we assume there is nothing more to
|
|
* process so we just return null...
|
|
*/
|
|
if (TupIsNull(slot))
|
|
{
|
|
result = NULL;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* if we have a junk filter, then project a new tuple with the
|
|
* junk removed.
|
|
*
|
|
* Store this new "clean" tuple in the place of the original tuple.
|
|
*
|
|
* Also, extract all the junk information we need.
|
|
*/
|
|
if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL)
|
|
{
|
|
Datum datum;
|
|
HeapTuple newTuple;
|
|
bool isNull;
|
|
|
|
/*
|
|
* extract the 'ctid' junk attribute.
|
|
*/
|
|
if (operation == CMD_UPDATE || operation == CMD_DELETE)
|
|
{
|
|
if (!ExecGetJunkAttribute(junkfilter,
|
|
slot,
|
|
"ctid",
|
|
&datum,
|
|
&isNull))
|
|
elog(ERROR, "ExecutePlan: NO (junk) `ctid' was found!");
|
|
|
|
if (isNull)
|
|
elog(ERROR, "ExecutePlan: (junk) `ctid' is NULL!");
|
|
|
|
tupleid = (ItemPointer) DatumGetPointer(datum);
|
|
tuple_ctid = *tupleid; /* make sure we don't free the
|
|
* ctid!! */
|
|
tupleid = &tuple_ctid;
|
|
}
|
|
else if (estate->es_rowMark != NIL)
|
|
{
|
|
List *l;
|
|
|
|
lmark: ;
|
|
foreach(l, estate->es_rowMark)
|
|
{
|
|
execRowMark *erm = lfirst(l);
|
|
Buffer buffer;
|
|
HeapTupleData tuple;
|
|
TupleTableSlot *newSlot;
|
|
int test;
|
|
|
|
if (!ExecGetJunkAttribute(junkfilter,
|
|
slot,
|
|
erm->resname,
|
|
&datum,
|
|
&isNull))
|
|
elog(ERROR, "ExecutePlan: NO (junk) `%s' was found!",
|
|
erm->resname);
|
|
|
|
if (isNull)
|
|
elog(ERROR, "ExecutePlan: (junk) `%s' is NULL!",
|
|
erm->resname);
|
|
|
|
tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
|
|
test = heap_mark4update(erm->relation, &tuple, &buffer);
|
|
ReleaseBuffer(buffer);
|
|
switch (test)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (XactIsoLevel == XACT_SERIALIZABLE)
|
|
{
|
|
elog(ERROR, "Can't serialize access due to concurrent update");
|
|
return (NULL);
|
|
}
|
|
else if (!(ItemPointerEquals(&(tuple.t_self),
|
|
(ItemPointer) DatumGetPointer(datum))))
|
|
{
|
|
newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
|
|
if (!(TupIsNull(newSlot)))
|
|
{
|
|
slot = newSlot;
|
|
estate->es_useEvalPlan = true;
|
|
goto lmark;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* if tuple was deleted or PlanQual failed for
|
|
* updated tuple - we have not return this
|
|
* tuple!
|
|
*/
|
|
goto lnext;
|
|
|
|
default:
|
|
elog(ERROR, "Unknown status %u from heap_mark4update", test);
|
|
return (NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Finally create a new "clean" tuple with all junk attributes
|
|
* removed
|
|
*/
|
|
newTuple = ExecRemoveJunk(junkfilter, slot);
|
|
|
|
slot = ExecStoreTuple(newTuple, /* tuple to store */
|
|
slot, /* destination slot */
|
|
InvalidBuffer, /* this tuple has no
|
|
* buffer */
|
|
true); /* tuple should be pfreed */
|
|
} /* if (junkfilter... */
|
|
|
|
/*
|
|
* now that we have a tuple, do the appropriate thing with it..
|
|
* either return it to the user, add it to a relation someplace,
|
|
* delete it from a relation, or modify some of its attributes.
|
|
*/
|
|
|
|
switch (operation)
|
|
{
|
|
case CMD_SELECT:
|
|
ExecRetrieve(slot, /* slot containing tuple */
|
|
destfunc, /* destination's tuple-receiver
|
|
* obj */
|
|
estate); /* */
|
|
result = slot;
|
|
break;
|
|
|
|
case CMD_INSERT:
|
|
ExecAppend(slot, tupleid, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
case CMD_DELETE:
|
|
ExecDelete(slot, tupleid, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
case CMD_UPDATE:
|
|
ExecReplace(slot, tupleid, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
default:
|
|
elog(DEBUG, "ExecutePlan: unknown operation in queryDesc");
|
|
result = NULL;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* check our tuple count.. if we've processed the proper number
|
|
* then quit, else loop again and process more tuples..
|
|
*/
|
|
current_tuple_count++;
|
|
if (numberTuples == current_tuple_count)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* here, result is either a slot containing a tuple in the case of a
|
|
* RETRIEVE or NULL otherwise.
|
|
*/
|
|
return result;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecRetrieve
|
|
*
|
|
* RETRIEVEs are easy.. we just pass the tuple to the appropriate
|
|
* print function. The only complexity is when we do a
|
|
* "retrieve into", in which case we insert the tuple into
|
|
* the appropriate relation (note: this is a newly created relation
|
|
* so we don't need to worry about indices or locks.)
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecRetrieve(TupleTableSlot *slot,
|
|
DestReceiver *destfunc,
|
|
EState *estate)
|
|
{
|
|
HeapTuple tuple;
|
|
TupleDesc attrtype;
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot
|
|
*/
|
|
tuple = slot->val;
|
|
attrtype = slot->ttc_tupleDescriptor;
|
|
|
|
/*
|
|
* insert the tuple into the "into relation"
|
|
*/
|
|
if (estate->es_into_relation_descriptor != NULL)
|
|
{
|
|
heap_insert(estate->es_into_relation_descriptor, tuple);
|
|
IncrAppended();
|
|
}
|
|
|
|
/*
|
|
* send the tuple to the front end (or the screen)
|
|
*/
|
|
(*destfunc->receiveTuple) (tuple, attrtype, destfunc);
|
|
IncrRetrieved();
|
|
(estate->es_processed)++;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecAppend
|
|
*
|
|
* APPENDs are trickier.. we have to insert the tuple into
|
|
* the base relation and insert appropriate tuples into the
|
|
* index relations.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
|
|
static void
|
|
ExecAppend(TupleTableSlot *slot,
|
|
ItemPointer tupleid,
|
|
EState *estate)
|
|
{
|
|
HeapTuple tuple;
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
int numIndices;
|
|
Oid newId;
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot
|
|
*/
|
|
tuple = slot->val;
|
|
|
|
/*
|
|
* get information on the (current) result relation
|
|
*/
|
|
resultRelInfo = estate->es_result_relation_info;
|
|
resultRelationDesc = resultRelInfo->ri_RelationDesc;
|
|
|
|
/* BEFORE ROW INSERT Triggers */
|
|
if (resultRelationDesc->trigdesc &&
|
|
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
|
|
{
|
|
HeapTuple newtuple;
|
|
|
|
newtuple = ExecBRInsertTriggers(resultRelationDesc, tuple);
|
|
|
|
if (newtuple == NULL) /* "do nothing" */
|
|
return;
|
|
|
|
if (newtuple != tuple) /* modified by Trigger(s) */
|
|
{
|
|
Assert(slot->ttc_shouldFree);
|
|
heap_freetuple(tuple);
|
|
slot->val = tuple = newtuple;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check the constraints of the tuple
|
|
*/
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints("ExecAppend", resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* insert the tuple
|
|
*/
|
|
newId = heap_insert(resultRelationDesc, tuple);
|
|
|
|
IncrAppended();
|
|
(estate->es_processed)++;
|
|
estate->es_lastoid = newId;
|
|
|
|
/*
|
|
* process indices
|
|
*
|
|
* Note: heap_insert adds a new tuple to a relation. As a side effect,
|
|
* the tupleid of the new tuple is placed in the new tuple's t_ctid
|
|
* field.
|
|
*/
|
|
numIndices = resultRelInfo->ri_NumIndices;
|
|
if (numIndices > 0)
|
|
ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
|
|
|
|
/* AFTER ROW INSERT Triggers */
|
|
if (resultRelationDesc->trigdesc)
|
|
ExecARInsertTriggers(resultRelationDesc, tuple);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecDelete
|
|
*
|
|
* DELETE is like append, we delete the tuple and its
|
|
* index tuples.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecDelete(TupleTableSlot *slot,
|
|
ItemPointer tupleid,
|
|
EState *estate)
|
|
{
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
ItemPointerData ctid;
|
|
int result;
|
|
|
|
/*
|
|
* get information on the (current) result relation
|
|
*/
|
|
resultRelInfo = estate->es_result_relation_info;
|
|
resultRelationDesc = resultRelInfo->ri_RelationDesc;
|
|
|
|
/* BEFORE ROW DELETE Triggers */
|
|
if (resultRelationDesc->trigdesc &&
|
|
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
|
|
{
|
|
bool dodelete;
|
|
|
|
dodelete = ExecBRDeleteTriggers(estate, tupleid);
|
|
|
|
if (!dodelete) /* "do nothing" */
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* delete the tuple
|
|
*/
|
|
ldelete:;
|
|
result = heap_delete(resultRelationDesc, tupleid, &ctid);
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
return;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (XactIsoLevel == XACT_SERIALIZABLE)
|
|
elog(ERROR, "Can't serialize access due to concurrent update");
|
|
else if (!(ItemPointerEquals(tupleid, &ctid)))
|
|
{
|
|
TupleTableSlot *epqslot = EvalPlanQual(estate,
|
|
resultRelInfo->ri_RangeTableIndex, &ctid);
|
|
|
|
if (!TupIsNull(epqslot))
|
|
{
|
|
*tupleid = ctid;
|
|
goto ldelete;
|
|
}
|
|
}
|
|
return;
|
|
|
|
default:
|
|
elog(ERROR, "Unknown status %u from heap_delete", result);
|
|
return;
|
|
}
|
|
|
|
IncrDeleted();
|
|
(estate->es_processed)++;
|
|
|
|
/*
|
|
* Note: Normally one would think that we have to delete index tuples
|
|
* associated with the heap tuple now..
|
|
*
|
|
* ... but in POSTGRES, we have no need to do this because the vacuum
|
|
* daemon automatically opens an index scan and deletes index tuples
|
|
* when it finds deleted heap tuples. -cim 9/27/89
|
|
*/
|
|
|
|
/* AFTER ROW DELETE Triggers */
|
|
if (resultRelationDesc->trigdesc)
|
|
ExecARDeleteTriggers(estate, tupleid);
|
|
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecReplace
|
|
*
|
|
* note: we can't run replace queries with transactions
|
|
* off because replaces are actually appends and our
|
|
* scan will mistakenly loop forever, replacing the tuple
|
|
* it just appended.. This should be fixed but until it
|
|
* is, we don't want to get stuck in an infinite loop
|
|
* which corrupts your database..
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecReplace(TupleTableSlot *slot,
|
|
ItemPointer tupleid,
|
|
EState *estate)
|
|
{
|
|
HeapTuple tuple;
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
ItemPointerData ctid;
|
|
int result;
|
|
int numIndices;
|
|
|
|
/*
|
|
* abort the operation if not running transactions
|
|
*/
|
|
if (IsBootstrapProcessingMode())
|
|
{
|
|
elog(NOTICE, "ExecReplace: replace can't run without transactions");
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot
|
|
*/
|
|
tuple = slot->val;
|
|
|
|
/*
|
|
* get information on the (current) result relation
|
|
*/
|
|
resultRelInfo = estate->es_result_relation_info;
|
|
resultRelationDesc = resultRelInfo->ri_RelationDesc;
|
|
|
|
/* BEFORE ROW UPDATE Triggers */
|
|
if (resultRelationDesc->trigdesc &&
|
|
resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
|
|
{
|
|
HeapTuple newtuple;
|
|
|
|
newtuple = ExecBRUpdateTriggers(estate, tupleid, tuple);
|
|
|
|
if (newtuple == NULL) /* "do nothing" */
|
|
return;
|
|
|
|
if (newtuple != tuple) /* modified by Trigger(s) */
|
|
{
|
|
Assert(slot->ttc_shouldFree);
|
|
heap_freetuple(tuple);
|
|
slot->val = tuple = newtuple;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check the constraints of the tuple
|
|
*/
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints("ExecReplace", resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* replace the heap tuple
|
|
*/
|
|
lreplace:;
|
|
result = heap_update(resultRelationDesc, tupleid, tuple, &ctid);
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
return;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (XactIsoLevel == XACT_SERIALIZABLE)
|
|
elog(ERROR, "Can't serialize access due to concurrent update");
|
|
else if (!(ItemPointerEquals(tupleid, &ctid)))
|
|
{
|
|
TupleTableSlot *epqslot = EvalPlanQual(estate,
|
|
resultRelInfo->ri_RangeTableIndex, &ctid);
|
|
|
|
if (!TupIsNull(epqslot))
|
|
{
|
|
*tupleid = ctid;
|
|
tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
|
|
slot = ExecStoreTuple(tuple, slot, InvalidBuffer, true);
|
|
goto lreplace;
|
|
}
|
|
}
|
|
return;
|
|
|
|
default:
|
|
elog(ERROR, "Unknown status %u from heap_update", result);
|
|
return;
|
|
}
|
|
|
|
IncrReplaced();
|
|
(estate->es_processed)++;
|
|
|
|
/*
|
|
* Note: instead of having to update the old index tuples associated
|
|
* with the heap tuple, all we do is form and insert new index
|
|
* tuples. This is because replaces are actually deletes and inserts
|
|
* and index tuple deletion is done automagically by the vacuum
|
|
* daemon. All we do is insert new index tuples. -cim 9/27/89
|
|
*/
|
|
|
|
/*
|
|
* process indices
|
|
*
|
|
* heap_update updates a tuple in the base relation by invalidating it
|
|
* and then appending a new tuple to the relation. As a side effect,
|
|
* the tupleid of the new tuple is placed in the new tuple's t_ctid
|
|
* field. So we now insert index tuples using the new tupleid stored
|
|
* there.
|
|
*/
|
|
|
|
numIndices = resultRelInfo->ri_NumIndices;
|
|
if (numIndices > 0)
|
|
ExecInsertIndexTuples(slot, &(tuple->t_self), estate, true);
|
|
|
|
/* AFTER ROW UPDATE Triggers */
|
|
if (resultRelationDesc->trigdesc)
|
|
ExecARUpdateTriggers(estate, tupleid, tuple);
|
|
}
|
|
|
|
static 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;
|
|
List *qual;
|
|
int i;
|
|
|
|
/*
|
|
* 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 =
|
|
(List **) palloc(ncheck * sizeof(List *));
|
|
for (i = 0; i < ncheck; i++)
|
|
{
|
|
qual = (List *) stringToNode(check[i].ccbin);
|
|
resultRelInfo->ri_ConstraintExprs[i] = qual;
|
|
}
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
|
|
/*
|
|
* We will use the EState's per-tuple context for evaluating constraint
|
|
* expressions. Create it if it's not already there; if it is, reset it
|
|
* to free previously-used storage.
|
|
*/
|
|
econtext = estate->es_per_tuple_exprcontext;
|
|
if (econtext == NULL)
|
|
{
|
|
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
|
|
estate->es_per_tuple_exprcontext = econtext =
|
|
MakeExprContext(NULL, estate->es_query_cxt);
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
else
|
|
ResetExprContext(econtext);
|
|
|
|
/* 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++)
|
|
{
|
|
qual = resultRelInfo->ri_ConstraintExprs[i];
|
|
|
|
/*
|
|
* NOTE: SQL92 specifies that a NULL result from a constraint
|
|
* expression is not to be treated as a failure. Therefore, tell
|
|
* ExecQual to return TRUE for NULL.
|
|
*/
|
|
if (!ExecQual(qual, econtext, true))
|
|
return check[i].ccname;
|
|
}
|
|
|
|
/* NULL result means no error */
|
|
return (char *) NULL;
|
|
}
|
|
|
|
void
|
|
ExecConstraints(char *caller, ResultRelInfo *resultRelInfo,
|
|
TupleTableSlot *slot, EState *estate)
|
|
{
|
|
Relation rel = resultRelInfo->ri_RelationDesc;
|
|
HeapTuple tuple = slot->val;
|
|
TupleConstr *constr = rel->rd_att->constr;
|
|
|
|
Assert(constr);
|
|
|
|
if (constr->has_not_null)
|
|
{
|
|
int natts = rel->rd_att->natts;
|
|
int attrChk;
|
|
|
|
for (attrChk = 1; attrChk <= natts; attrChk++)
|
|
{
|
|
if (rel->rd_att->attrs[attrChk-1]->attnotnull &&
|
|
heap_attisnull(tuple, attrChk))
|
|
elog(ERROR, "%s: Fail to add null value in not null attribute %s",
|
|
caller, NameStr(rel->rd_att->attrs[attrChk-1]->attname));
|
|
}
|
|
}
|
|
|
|
if (constr->num_check > 0)
|
|
{
|
|
char *failed;
|
|
|
|
if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
|
|
elog(ERROR, "%s: rejected due to CHECK constraint %s",
|
|
caller, failed);
|
|
}
|
|
}
|
|
|
|
TupleTableSlot *
|
|
EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
|
|
{
|
|
evalPlanQual *epq = (evalPlanQual *) estate->es_evalPlanQual;
|
|
evalPlanQual *oldepq;
|
|
EState *epqstate = NULL;
|
|
Relation relation;
|
|
Buffer buffer;
|
|
HeapTupleData tuple;
|
|
bool endNode = true;
|
|
|
|
Assert(rti != 0);
|
|
|
|
if (epq != NULL && epq->rti == 0)
|
|
{
|
|
Assert(!(estate->es_useEvalPlan) &&
|
|
epq->estate.es_evalPlanQual == NULL);
|
|
epq->rti = rti;
|
|
endNode = false;
|
|
}
|
|
|
|
/*
|
|
* If this is request for another RTE - Ra, - then we have to check
|
|
* wasn't PlanQual requested for Ra already and if so then Ra' row was
|
|
* updated again and we have to re-start old execution for Ra and
|
|
* forget all what we done after Ra was suspended. Cool? -:))
|
|
*/
|
|
if (epq != NULL && epq->rti != rti &&
|
|
epq->estate.es_evTuple[rti - 1] != NULL)
|
|
{
|
|
do
|
|
{
|
|
/* pop previous PlanQual from the stack */
|
|
epqstate = &(epq->estate);
|
|
oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
|
|
Assert(oldepq->rti != 0);
|
|
/* stop execution */
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
epqstate->es_tupleTable->next = 0;
|
|
heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
|
|
epqstate->es_evTuple[epq->rti - 1] = NULL;
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
} while (epq->rti != rti);
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
}
|
|
|
|
/*
|
|
* If we are requested for another RTE then we have to suspend
|
|
* execution of current PlanQual and start execution for new one.
|
|
*/
|
|
if (epq == NULL || epq->rti != rti)
|
|
{
|
|
/* try to reuse plan used previously */
|
|
evalPlanQual *newepq = (epq != NULL) ? epq->free : NULL;
|
|
|
|
if (newepq == NULL) /* first call or freePQ stack is empty */
|
|
{
|
|
newepq = (evalPlanQual *) palloc(sizeof(evalPlanQual));
|
|
/* Init EState */
|
|
epqstate = &(newepq->estate);
|
|
memset(epqstate, 0, sizeof(EState));
|
|
epqstate->type = T_EState;
|
|
epqstate->es_direction = ForwardScanDirection;
|
|
epqstate->es_snapshot = estate->es_snapshot;
|
|
epqstate->es_range_table = estate->es_range_table;
|
|
epqstate->es_param_list_info = estate->es_param_list_info;
|
|
if (estate->es_origPlan->nParamExec > 0)
|
|
epqstate->es_param_exec_vals = (ParamExecData *)
|
|
palloc(estate->es_origPlan->nParamExec *
|
|
sizeof(ParamExecData));
|
|
epqstate->es_tupleTable =
|
|
ExecCreateTupleTable(estate->es_tupleTable->size);
|
|
/* ... rest */
|
|
newepq->plan = copyObject(estate->es_origPlan);
|
|
newepq->free = NULL;
|
|
epqstate->es_evTupleNull = (bool *)
|
|
palloc(length(estate->es_range_table) * sizeof(bool));
|
|
if (epq == NULL) /* first call */
|
|
{
|
|
epqstate->es_evTuple = (HeapTuple *)
|
|
palloc(length(estate->es_range_table) * sizeof(HeapTuple));
|
|
memset(epqstate->es_evTuple, 0,
|
|
length(estate->es_range_table) * sizeof(HeapTuple));
|
|
}
|
|
else
|
|
epqstate->es_evTuple = epq->estate.es_evTuple;
|
|
}
|
|
else
|
|
epqstate = &(newepq->estate);
|
|
/* push current PQ to the stack */
|
|
epqstate->es_evalPlanQual = (Pointer) epq;
|
|
epq = newepq;
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
epq->rti = rti;
|
|
endNode = false;
|
|
}
|
|
|
|
epqstate = &(epq->estate);
|
|
|
|
/*
|
|
* Ok - we're requested for the same RTE (-:)). I'm not sure about
|
|
* ability to use ExecReScan instead of ExecInitNode, so...
|
|
*/
|
|
if (endNode)
|
|
{
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
epqstate->es_tupleTable->next = 0;
|
|
}
|
|
|
|
/* free old RTE' tuple */
|
|
if (epqstate->es_evTuple[epq->rti - 1] != NULL)
|
|
{
|
|
heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
|
|
epqstate->es_evTuple[epq->rti - 1] = NULL;
|
|
}
|
|
|
|
/* ** fetch tid tuple ** */
|
|
if (estate->es_result_relation_info != NULL &&
|
|
estate->es_result_relation_info->ri_RangeTableIndex == rti)
|
|
relation = estate->es_result_relation_info->ri_RelationDesc;
|
|
else
|
|
{
|
|
List *l;
|
|
|
|
foreach(l, estate->es_rowMark)
|
|
{
|
|
if (((execRowMark *) lfirst(l))->rti == rti)
|
|
break;
|
|
}
|
|
relation = ((execRowMark *) lfirst(l))->relation;
|
|
}
|
|
tuple.t_self = *tid;
|
|
for (;;)
|
|
{
|
|
heap_fetch(relation, SnapshotDirty, &tuple, &buffer);
|
|
if (tuple.t_data != NULL)
|
|
{
|
|
TransactionId xwait = SnapshotDirty->xmax;
|
|
|
|
if (TransactionIdIsValid(SnapshotDirty->xmin))
|
|
{
|
|
elog(NOTICE, "EvalPlanQual: t_xmin is uncommitted ?!");
|
|
Assert(!TransactionIdIsValid(SnapshotDirty->xmin));
|
|
elog(ERROR, "Aborting this transaction");
|
|
}
|
|
|
|
/*
|
|
* If tuple is being updated by other transaction then we have
|
|
* to wait for its commit/abort.
|
|
*/
|
|
if (TransactionIdIsValid(xwait))
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
XactLockTableWait(xwait);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Nice! We got tuple - now copy it.
|
|
*/
|
|
if (epqstate->es_evTuple[epq->rti - 1] != NULL)
|
|
heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
|
|
epqstate->es_evTuple[epq->rti - 1] = heap_copytuple(&tuple);
|
|
ReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Ops! Invalid tuple. Have to check is it updated or deleted.
|
|
* Note that it's possible to get invalid SnapshotDirty->tid if
|
|
* tuple updated by this transaction. Have we to check this ?
|
|
*/
|
|
if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
|
|
!(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
|
|
{
|
|
tuple.t_self = SnapshotDirty->tid; /* updated ... */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Deleted or updated by this transaction. Do not (re-)start
|
|
* execution of this PQ. Continue previous PQ.
|
|
*/
|
|
oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
|
|
if (oldepq != NULL)
|
|
{
|
|
Assert(oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
epqstate = &(epq->estate);
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
}
|
|
else
|
|
{
|
|
epq->rti = 0; /* this is the first (oldest) */
|
|
estate->es_useEvalPlan = false; /* PQ - mark as free and */
|
|
return (NULL); /* continue Query execution */
|
|
}
|
|
}
|
|
|
|
if (estate->es_origPlan->nParamExec > 0)
|
|
memset(epqstate->es_param_exec_vals, 0,
|
|
estate->es_origPlan->nParamExec * sizeof(ParamExecData));
|
|
memset(epqstate->es_evTupleNull, false,
|
|
length(estate->es_range_table) * sizeof(bool));
|
|
Assert(epqstate->es_tupleTable->next == 0);
|
|
ExecInitNode(epq->plan, epqstate, NULL);
|
|
|
|
/*
|
|
* For UPDATE/DELETE we have to return tid of actual row we're
|
|
* executing PQ for.
|
|
*/
|
|
*tid = tuple.t_self;
|
|
|
|
return EvalPlanQualNext(estate);
|
|
}
|
|
|
|
static TupleTableSlot *
|
|
EvalPlanQualNext(EState *estate)
|
|
{
|
|
evalPlanQual *epq = (evalPlanQual *) estate->es_evalPlanQual;
|
|
EState *epqstate = &(epq->estate);
|
|
evalPlanQual *oldepq;
|
|
TupleTableSlot *slot;
|
|
|
|
Assert(epq->rti != 0);
|
|
|
|
lpqnext:;
|
|
slot = ExecProcNode(epq->plan, epq->plan);
|
|
|
|
/*
|
|
* No more tuples for this PQ. Continue previous one.
|
|
*/
|
|
if (TupIsNull(slot))
|
|
{
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
epqstate->es_tupleTable->next = 0;
|
|
heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
|
|
epqstate->es_evTuple[epq->rti - 1] = NULL;
|
|
/* pop old PQ from the stack */
|
|
oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
|
|
if (oldepq == (evalPlanQual *) NULL)
|
|
{
|
|
epq->rti = 0; /* this is the first (oldest) */
|
|
estate->es_useEvalPlan = false; /* PQ - mark as free and */
|
|
return (NULL); /* continue Query execution */
|
|
}
|
|
Assert(oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
epqstate = &(epq->estate);
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
goto lpqnext;
|
|
}
|
|
|
|
return (slot);
|
|
}
|
|
|
|
static void
|
|
EndEvalPlanQual(EState *estate)
|
|
{
|
|
evalPlanQual *epq = (evalPlanQual *) estate->es_evalPlanQual;
|
|
EState *epqstate = &(epq->estate);
|
|
evalPlanQual *oldepq;
|
|
|
|
if (epq->rti == 0) /* plans already shutdowned */
|
|
{
|
|
Assert(epq->estate.es_evalPlanQual == NULL);
|
|
return;
|
|
}
|
|
|
|
for (;;)
|
|
{
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
epqstate->es_tupleTable->next = 0;
|
|
if (epqstate->es_evTuple[epq->rti - 1] != NULL)
|
|
{
|
|
heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
|
|
epqstate->es_evTuple[epq->rti - 1] = NULL;
|
|
}
|
|
/* pop old PQ from the stack */
|
|
oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
|
|
if (oldepq == (evalPlanQual *) NULL)
|
|
{
|
|
epq->rti = 0; /* this is the first (oldest) */
|
|
estate->es_useEvalPlan = false; /* PQ - mark as free */
|
|
break;
|
|
}
|
|
Assert(oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
epqstate = &(epq->estate);
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
}
|
|
}
|