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1973 lines
50 KiB
C
1973 lines
50 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* The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2001, PostgreSQL Global Development Group
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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 1.146 2001/09/08 16:15:28 inoue 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 execution of any
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* query plan
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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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if (estate->es_snapshot != NULL)
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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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estate->es_snapshot = NULL;
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}
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if (estate->es_param_exec_vals != NULL)
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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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* 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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* userid to check as: current user unless we have a setuid
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* indication.
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*
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* Note: GetUserId() is presently fast enough that there's no harm in
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* calling it separately for each RTE. If that stops being true, we
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* could call it once in ExecCheckQueryPerms and pass the userid down
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* 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_SELECT);
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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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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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aclcheck_result = CHECK(ACL_INSERT);
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break;
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case CMD_SELECT:
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case CMD_UPDATE:
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aclcheck_result = CHECK(ACL_UPDATE);
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break;
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case CMD_DELETE:
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aclcheck_result = CHECK(ACL_DELETE);
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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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}
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/* ===============================================================
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* ===============================================================
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static routines follow
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* ===============================================================
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* ===============================================================
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*/
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typedef struct execRowMark
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{
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Relation relation;
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Index rti;
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char resname[32];
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} execRowMark;
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typedef struct evalPlanQual
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{
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Plan *plan;
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Index rti;
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EState estate;
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struct evalPlanQual *free;
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} evalPlanQual;
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/* ----------------------------------------------------------------
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* InitPlan
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*
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* Initializes the query plan: open files, allocate storage
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* and start up the rule manager
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* ----------------------------------------------------------------
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*/
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static TupleDesc
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InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
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{
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List *rangeTable;
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Relation intoRelationDesc;
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TupleDesc tupType;
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/*
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* Do permissions checks.
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*/
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ExecCheckQueryPerms(operation, parseTree, plan);
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/*
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* get information from query descriptor
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*/
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rangeTable = parseTree->rtable;
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/*
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* initialize the node's execution state
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*/
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estate->es_range_table = rangeTable;
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/*
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* if there is a result relation, initialize result relation stuff
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*/
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if (parseTree->resultRelation != 0 && operation != CMD_SELECT)
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{
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List *resultRelations = parseTree->resultRelations;
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int numResultRelations;
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ResultRelInfo *resultRelInfos;
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if (resultRelations != NIL)
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{
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/*
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* Multiple result relations (due to inheritance)
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* parseTree->resultRelations identifies them all
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*/
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ResultRelInfo *resultRelInfo;
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numResultRelations = length(resultRelations);
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resultRelInfos = (ResultRelInfo *)
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palloc(numResultRelations * sizeof(ResultRelInfo));
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resultRelInfo = resultRelInfos;
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while (resultRelations != NIL)
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{
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initResultRelInfo(resultRelInfo,
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lfirsti(resultRelations),
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rangeTable,
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operation);
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resultRelInfo++;
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resultRelations = lnext(resultRelations);
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}
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}
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else
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{
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/*
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* Single result relation identified by
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* parseTree->resultRelation
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*/
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numResultRelations = 1;
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resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
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initResultRelInfo(resultRelInfos,
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parseTree->resultRelation,
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rangeTable,
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operation);
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}
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estate->es_result_relations = resultRelInfos;
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estate->es_num_result_relations = numResultRelations;
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/* Initialize to first or only result rel */
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estate->es_result_relation_info = resultRelInfos;
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}
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else
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{
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/*
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* if no result relation, then set state appropriately
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*/
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estate->es_result_relations = NULL;
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estate->es_num_result_relations = 0;
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estate->es_result_relation_info = NULL;
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}
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/*
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* Have to lock relations selected for update
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*/
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estate->es_rowMark = NIL;
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if (parseTree->rowMarks != NIL)
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{
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List *l;
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foreach(l, parseTree->rowMarks)
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{
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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. We need slots for all the
|
|
* plan nodes, plus possibly output slots for the junkfilter(s).
|
|
* At this point we aren't sure if we need junkfilters, so just add
|
|
* slots for them unconditionally.
|
|
*/
|
|
{
|
|
int nSlots = ExecCountSlotsNode(plan);
|
|
|
|
if (parseTree->resultRelations != NIL)
|
|
nSlots += length(parseTree->resultRelations);
|
|
else
|
|
nSlots += 1;
|
|
estate->es_tupleTable = ExecCreateTupleTable(nSlots);
|
|
}
|
|
|
|
/* mark EvalPlanQual not active */
|
|
estate->es_origPlan = plan;
|
|
estate->es_evalPlanQual = NULL;
|
|
estate->es_evTuple = NULL;
|
|
estate->es_evTupleNull = NULL;
|
|
estate->es_useEvalPlan = false;
|
|
|
|
/*
|
|
* 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),
|
|
ExecAllocTableSlot(estate->es_tupleTable));
|
|
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;
|
|
|
|
j = ExecInitJunkFilter(plan->targetlist,
|
|
tupType,
|
|
ExecAllocTableSlot(estate->es_tupleTable));
|
|
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, true,
|
|
parseTree->isTemp,
|
|
allowSystemTableMods);
|
|
|
|
FreeTupleDesc(tupdesc);
|
|
|
|
/*
|
|
* Advance command counter so that the newly-created
|
|
* relation's catalog tuples will be visible to heap_open.
|
|
*/
|
|
CommandCounterIncrement();
|
|
|
|
/*
|
|
* If necessary, create a TOAST table for the into
|
|
* relation. Note that AlterTableCreateToastTable ends
|
|
* with CommandCounterIncrement(), so that the TOAST table
|
|
* will be visible for insertion.
|
|
*/
|
|
AlterTableCreateToastTable(intoName, true);
|
|
|
|
intoRelationDesc = heap_open(intoRelationId,
|
|
AccessExclusiveLock);
|
|
}
|
|
}
|
|
}
|
|
|
|
estate->es_into_relation_descriptor = intoRelationDesc;
|
|
|
|
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_TrigDesc = resultRelationDesc->trigdesc;
|
|
resultRelInfo->ri_TrigFunctions = 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. Also clean up junkfilters if present.
|
|
*/
|
|
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);
|
|
/* Delete the junkfilter if any */
|
|
if (resultRelInfo->ri_junkFilter != NULL)
|
|
ExecFreeJunkFilter(resultRelInfo->ri_junkFilter);
|
|
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);
|
|
|
|
/*
|
|
* There might be a junkfilter without a result relation.
|
|
*/
|
|
if (estate->es_num_result_relations == 0 &&
|
|
estate->es_junkFilter != NULL)
|
|
{
|
|
ExecFreeJunkFilter(estate->es_junkFilter);
|
|
estate->es_junkFilter = NULL;
|
|
}
|
|
|
|
/*
|
|
* 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 (;;)
|
|
{
|
|
/* Reset the per-output-tuple exprcontext */
|
|
ResetPerTupleExprContext(estate);
|
|
|
|
/*
|
|
* 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 junkfilter's resultSlot.
|
|
* (Formerly, we stored it back over the "dirty" tuple, which is
|
|
* WRONG because that tuple slot has the wrong descriptor.)
|
|
*
|
|
* 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!");
|
|
|
|
/* shouldn't ever get a null result... */
|
|
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);
|
|
|
|
/* shouldn't ever get a null result... */
|
|
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");
|
|
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 must 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 */
|
|
junkfilter->jf_resultSlot, /* dest 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 (resultRelInfo->ri_TrigDesc &&
|
|
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
|
|
{
|
|
HeapTuple newtuple;
|
|
|
|
newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
|
|
|
|
if (newtuple == NULL) /* "do nothing" */
|
|
return;
|
|
|
|
if (newtuple != tuple) /* modified by Trigger(s) */
|
|
{
|
|
|
|
/*
|
|
* Insert modified tuple into tuple table slot, replacing the
|
|
* original. We assume that it was allocated in per-tuple
|
|
* memory context, and therefore will go away by itself. The
|
|
* tuple table slot should not try to clear it.
|
|
*/
|
|
ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
|
|
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);
|
|
setLastTid(&(tuple->t_self));
|
|
|
|
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 (resultRelInfo->ri_TrigDesc)
|
|
ExecARInsertTriggers(estate, resultRelInfo, 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 (resultRelInfo->ri_TrigDesc &&
|
|
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
|
|
{
|
|
bool dodelete;
|
|
|
|
dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, 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;
|
|
}
|
|
}
|
|
/* tuple already deleted; nothing to do */
|
|
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 (resultRelInfo->ri_TrigDesc)
|
|
ExecARDeleteTriggers(estate, resultRelInfo, 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 (resultRelInfo->ri_TrigDesc &&
|
|
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
|
|
{
|
|
HeapTuple newtuple;
|
|
|
|
newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
|
|
tupleid, tuple);
|
|
|
|
if (newtuple == NULL) /* "do nothing" */
|
|
return;
|
|
|
|
if (newtuple != tuple) /* modified by Trigger(s) */
|
|
{
|
|
|
|
/*
|
|
* Insert modified tuple into tuple table slot, replacing the
|
|
* original. We assume that it was allocated in per-tuple
|
|
* memory context, and therefore will go away by itself. The
|
|
* tuple table slot should not try to clear it.
|
|
*/
|
|
ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
|
|
tuple = newtuple;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check the constraints of the tuple
|
|
*
|
|
* If we generate a new candidate tuple after EvalPlanQual testing,
|
|
* we must loop back here and recheck constraints. (We don't need to
|
|
* redo triggers, however. If there are any BEFORE triggers then
|
|
* trigger.c will have done mark4update to lock the correct tuple,
|
|
* so there's no need to do them again.)
|
|
*/
|
|
lreplace:;
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints("ExecReplace", resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* replace the heap tuple
|
|
*/
|
|
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,
|
|
estate->es_junkFilter->jf_resultSlot,
|
|
InvalidBuffer, true);
|
|
goto lreplace;
|
|
}
|
|
}
|
|
/* tuple already deleted; nothing to do */
|
|
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 (resultRelInfo->ri_TrigDesc)
|
|
ExecARUpdateTriggers(estate, resultRelInfo, 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 (creating it if it's not already there).
|
|
*/
|
|
econtext = GetPerTupleExprContext(estate);
|
|
|
|
/* Arrange for econtext's scan tuple to be the tuple under test */
|
|
econtext->ecxt_scantuple = slot;
|
|
|
|
/* And evaluate the constraints */
|
|
for (i = 0; i < ncheck; i++)
|
|
{
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check a modified tuple to see if we want to process its updated version
|
|
* under READ COMMITTED rules.
|
|
*
|
|
* See backend/executor/README for some info about how this works.
|
|
*/
|
|
TupleTableSlot *
|
|
EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
|
|
{
|
|
evalPlanQual *epq;
|
|
EState *epqstate;
|
|
Relation relation;
|
|
HeapTupleData tuple;
|
|
HeapTuple copyTuple = NULL;
|
|
int rtsize;
|
|
bool endNode;
|
|
|
|
Assert(rti != 0);
|
|
|
|
/*
|
|
* find relation containing target 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;
|
|
|
|
relation = NULL;
|
|
foreach(l, estate->es_rowMark)
|
|
{
|
|
if (((execRowMark *) lfirst(l))->rti == rti)
|
|
{
|
|
relation = ((execRowMark *) lfirst(l))->relation;
|
|
break;
|
|
}
|
|
}
|
|
if (relation == NULL)
|
|
elog(ERROR, "EvalPlanQual: can't find RTE %d", (int) rti);
|
|
}
|
|
|
|
/*
|
|
* fetch tid tuple
|
|
*
|
|
* Loop here to deal with updated or busy tuples
|
|
*/
|
|
tuple.t_self = *tid;
|
|
for (;;)
|
|
{
|
|
Buffer buffer;
|
|
|
|
heap_fetch(relation, SnapshotDirty, &tuple, &buffer, NULL);
|
|
if (tuple.t_data != NULL)
|
|
{
|
|
TransactionId xwait = SnapshotDirty->xmax;
|
|
|
|
if (TransactionIdIsValid(SnapshotDirty->xmin))
|
|
elog(ERROR, "EvalPlanQual: t_xmin is uncommitted ?!");
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* We got tuple - now copy it for use by recheck query.
|
|
*/
|
|
copyTuple = heap_copytuple(&tuple);
|
|
ReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Oops! 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))))
|
|
{
|
|
/* updated, so look at the updated copy */
|
|
tuple.t_self = SnapshotDirty->tid;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Deleted or updated by this transaction; forget it.
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* For UPDATE/DELETE we have to return tid of actual row we're
|
|
* executing PQ for.
|
|
*/
|
|
*tid = tuple.t_self;
|
|
|
|
/*
|
|
* Need to run a recheck subquery. Find or create a PQ stack entry.
|
|
*/
|
|
epq = (evalPlanQual *) estate->es_evalPlanQual;
|
|
rtsize = length(estate->es_range_table);
|
|
endNode = true;
|
|
|
|
if (epq != NULL && epq->rti == 0)
|
|
{
|
|
/* Top PQ stack entry is idle, so re-use it */
|
|
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
|
|
{
|
|
evalPlanQual *oldepq;
|
|
|
|
/* 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);
|
|
ExecDropTupleTable(epqstate->es_tupleTable, true);
|
|
epqstate->es_tupleTable = NULL;
|
|
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;
|
|
estate->es_evalPlanQual = (Pointer) epq;
|
|
} while (epq->rti != rti);
|
|
}
|
|
|
|
/*
|
|
* 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));
|
|
newepq->free = NULL;
|
|
/*
|
|
* Each stack level has its own copy of the plan tree. This
|
|
* is wasteful, but necessary as long as plan nodes point to
|
|
* exec state nodes rather than vice versa. Note that copyfuncs.c
|
|
* doesn't attempt to copy the exec state nodes, which is a good
|
|
* thing in this situation.
|
|
*/
|
|
newepq->plan = copyObject(estate->es_origPlan);
|
|
/*
|
|
* Init stack level's EState. We share top level's copy of
|
|
* es_result_relations array and other non-changing status.
|
|
* We need our own tupletable, es_param_exec_vals, and other
|
|
* changeable state.
|
|
*/
|
|
epqstate = &(newepq->estate);
|
|
memcpy(epqstate, estate, sizeof(EState));
|
|
epqstate->es_direction = ForwardScanDirection;
|
|
if (estate->es_origPlan->nParamExec > 0)
|
|
epqstate->es_param_exec_vals = (ParamExecData *)
|
|
palloc(estate->es_origPlan->nParamExec *
|
|
sizeof(ParamExecData));
|
|
epqstate->es_tupleTable = NULL;
|
|
epqstate->es_per_tuple_exprcontext = NULL;
|
|
/*
|
|
* Each epqstate must have its own es_evTupleNull state,
|
|
* but all the stack entries share es_evTuple state. This
|
|
* allows sub-rechecks to inherit the value being examined by
|
|
* an outer recheck.
|
|
*/
|
|
epqstate->es_evTupleNull = (bool *) palloc(rtsize * sizeof(bool));
|
|
if (epq == NULL)
|
|
{
|
|
/* first PQ stack entry */
|
|
epqstate->es_evTuple = (HeapTuple *)
|
|
palloc(rtsize * sizeof(HeapTuple));
|
|
memset(epqstate->es_evTuple, 0, rtsize * sizeof(HeapTuple));
|
|
}
|
|
else
|
|
{
|
|
/* later stack entries share the same storage */
|
|
epqstate->es_evTuple = epq->estate.es_evTuple;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* recycle previously used EState */
|
|
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;
|
|
}
|
|
|
|
Assert(epq->rti == rti);
|
|
epqstate = &(epq->estate);
|
|
|
|
/*
|
|
* Ok - we're requested for the same RTE. Unfortunately we still
|
|
* have to end and restart execution of the plan, because ExecReScan
|
|
* wouldn't ensure that upper plan nodes would reset themselves. We
|
|
* could make that work if insertion of the target tuple were integrated
|
|
* with the Param mechanism somehow, so that the upper plan nodes know
|
|
* that their children's outputs have changed.
|
|
*/
|
|
if (endNode)
|
|
{
|
|
/* stop execution */
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
ExecDropTupleTable(epqstate->es_tupleTable, true);
|
|
epqstate->es_tupleTable = NULL;
|
|
}
|
|
|
|
/*
|
|
* free old RTE' tuple, if any, and store target tuple where relation's
|
|
* scan node will see it
|
|
*/
|
|
if (epqstate->es_evTuple[rti - 1] != NULL)
|
|
heap_freetuple(epqstate->es_evTuple[rti - 1]);
|
|
epqstate->es_evTuple[rti - 1] = copyTuple;
|
|
|
|
/*
|
|
* Initialize for new recheck query; be careful to copy down state
|
|
* that might have changed in top EState.
|
|
*/
|
|
epqstate->es_result_relation_info = estate->es_result_relation_info;
|
|
epqstate->es_junkFilter = estate->es_junkFilter;
|
|
if (estate->es_origPlan->nParamExec > 0)
|
|
memset(epqstate->es_param_exec_vals, 0,
|
|
estate->es_origPlan->nParamExec * sizeof(ParamExecData));
|
|
memset(epqstate->es_evTupleNull, false, rtsize * sizeof(bool));
|
|
epqstate->es_useEvalPlan = false;
|
|
Assert(epqstate->es_tupleTable == NULL);
|
|
epqstate->es_tupleTable =
|
|
ExecCreateTupleTable(estate->es_tupleTable->size);
|
|
|
|
ExecInitNode(epq->plan, epqstate, NULL);
|
|
|
|
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))
|
|
{
|
|
/* stop execution */
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
ExecDropTupleTable(epqstate->es_tupleTable, true);
|
|
epqstate->es_tupleTable = 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 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 (;;)
|
|
{
|
|
/* stop execution */
|
|
ExecEndNode(epq->plan, epq->plan);
|
|
ExecDropTupleTable(epqstate->es_tupleTable, true);
|
|
epqstate->es_tupleTable = NULL;
|
|
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;
|
|
}
|
|
}
|