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2578 lines
70 KiB
C
2578 lines
70 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* The old ExecutorMain() has been replaced by ExecutorStart(),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 is required as an argument.
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*
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* ExecutorStart() must be called at the beginning of 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 direction 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) 1996-2006, 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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* $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.280 2006/10/04 00:29:52 momjian 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 "access/reloptions.h"
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#include "access/transam.h"
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#include "access/xact.h"
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#include "catalog/heap.h"
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#include "catalog/namespace.h"
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#include "catalog/toasting.h"
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#include "commands/tablespace.h"
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#include "commands/trigger.h"
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#include "executor/execdebug.h"
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#include "executor/instrument.h"
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#include "executor/nodeSubplan.h"
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#include "miscadmin.h"
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#include "optimizer/clauses.h"
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#include "parser/parse_clause.h"
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#include "parser/parsetree.h"
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#include "storage/smgr.h"
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#include "utils/acl.h"
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#include "utils/lsyscache.h"
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#include "utils/memutils.h"
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typedef struct evalPlanQual
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{
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Index rti;
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EState *estate;
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PlanState *planstate;
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struct evalPlanQual *next; /* stack of active PlanQual plans */
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struct evalPlanQual *free; /* list of free PlanQual plans */
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} evalPlanQual;
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/* decls for local routines only used within this module */
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static void InitPlan(QueryDesc *queryDesc, int eflags);
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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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bool doInstrument);
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static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
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CmdType operation,
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long numberTuples,
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ScanDirection direction,
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DestReceiver *dest);
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static void ExecSelect(TupleTableSlot *slot,
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DestReceiver *dest, EState *estate);
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static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
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TupleTableSlot *planSlot,
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DestReceiver *dest, EState *estate);
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static void ExecDelete(ItemPointer tupleid,
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TupleTableSlot *planSlot,
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DestReceiver *dest, EState *estate);
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static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
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TupleTableSlot *planSlot,
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DestReceiver *dest, EState *estate);
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static void ExecProcessReturning(ProjectionInfo *projectReturning,
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TupleTableSlot *tupleSlot,
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TupleTableSlot *planSlot,
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DestReceiver *dest);
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static TupleTableSlot *EvalPlanQualNext(EState *estate);
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static void EndEvalPlanQual(EState *estate);
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static void ExecCheckRTEPerms(RangeTblEntry *rte);
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static void ExecCheckXactReadOnly(Query *parsetree);
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static void EvalPlanQualStart(evalPlanQual *epq, EState *estate,
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evalPlanQual *priorepq);
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static void EvalPlanQualStop(evalPlanQual *epq);
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static void OpenIntoRel(QueryDesc *queryDesc);
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static void CloseIntoRel(QueryDesc *queryDesc);
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static void intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo);
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static void intorel_receive(TupleTableSlot *slot, DestReceiver *self);
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static void intorel_shutdown(DestReceiver *self);
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static void intorel_destroy(DestReceiver *self);
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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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* Takes a QueryDesc previously created by CreateQueryDesc (it's not real
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* clear why we bother to separate the two functions, but...). The tupDesc
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* field of the QueryDesc is filled in to describe the tuples that will be
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* returned, and the internal fields (estate and planstate) are set up.
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*
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* eflags contains flag bits as described in executor.h.
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*
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* NB: the CurrentMemoryContext when this is called will become the parent
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* of the per-query context used for this Executor invocation.
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* ----------------------------------------------------------------
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*/
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void
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ExecutorStart(QueryDesc *queryDesc, int eflags)
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{
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EState *estate;
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MemoryContext oldcontext;
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/* sanity checks: queryDesc must not be started already */
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Assert(queryDesc != NULL);
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Assert(queryDesc->estate == NULL);
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/*
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* If the transaction is read-only, we need to check if any writes are
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* planned to non-temporary tables. EXPLAIN is considered read-only.
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*/
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if (XactReadOnly && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
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ExecCheckXactReadOnly(queryDesc->parsetree);
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/*
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* Build EState, switch into per-query memory context for startup.
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*/
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estate = CreateExecutorState();
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queryDesc->estate = estate;
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oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
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/*
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* Fill in parameters, if any, from queryDesc
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*/
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estate->es_param_list_info = queryDesc->params;
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if (queryDesc->plantree->nParamExec > 0)
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estate->es_param_exec_vals = (ParamExecData *)
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palloc0(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
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/*
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* Copy other important information into the EState
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*/
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estate->es_snapshot = queryDesc->snapshot;
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estate->es_crosscheck_snapshot = queryDesc->crosscheck_snapshot;
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estate->es_instrument = queryDesc->doInstrument;
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/*
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* Initialize the plan state tree
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*/
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InitPlan(queryDesc, eflags);
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MemoryContextSwitchTo(oldcontext);
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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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* If direction is NoMovementScanDirection then nothing is done
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* except to start up/shut down the destination. Otherwise,
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* we retrieve up to 'count' tuples in the specified direction.
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*
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* Note: count = 0 is interpreted as no portal limit, i.e., run to
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* completion.
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*
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* ----------------------------------------------------------------
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*/
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TupleTableSlot *
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ExecutorRun(QueryDesc *queryDesc,
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ScanDirection direction, long count)
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{
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EState *estate;
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CmdType operation;
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DestReceiver *dest;
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bool sendTuples;
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TupleTableSlot *result;
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MemoryContext oldcontext;
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/* sanity checks */
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Assert(queryDesc != NULL);
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estate = queryDesc->estate;
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Assert(estate != NULL);
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/*
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* Switch into per-query memory context
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*/
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oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
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/*
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* extract information from the query descriptor and the query feature.
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*/
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operation = queryDesc->operation;
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dest = queryDesc->dest;
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/*
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* startup tuple receiver, if we will be emitting tuples
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*/
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estate->es_processed = 0;
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estate->es_lastoid = InvalidOid;
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sendTuples = (operation == CMD_SELECT ||
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queryDesc->parsetree->returningList);
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if (sendTuples)
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(*dest->rStartup) (dest, operation, queryDesc->tupDesc);
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/*
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* run plan
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*/
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if (ScanDirectionIsNoMovement(direction))
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result = NULL;
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else
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result = ExecutePlan(estate,
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queryDesc->planstate,
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operation,
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count,
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direction,
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dest);
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/*
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* shutdown tuple receiver, if we started it
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*/
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if (sendTuples)
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(*dest->rShutdown) (dest);
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MemoryContextSwitchTo(oldcontext);
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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)
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{
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EState *estate;
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MemoryContext oldcontext;
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/* sanity checks */
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Assert(queryDesc != NULL);
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estate = queryDesc->estate;
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Assert(estate != NULL);
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/*
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* Switch into per-query memory context to run ExecEndPlan
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*/
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oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
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ExecEndPlan(queryDesc->planstate, estate);
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/*
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* Close the SELECT INTO relation if any
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*/
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if (estate->es_select_into)
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CloseIntoRel(queryDesc);
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/*
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* Must switch out of context before destroying it
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*/
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MemoryContextSwitchTo(oldcontext);
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/*
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* Release EState and per-query memory context. This should release
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* everything the executor has allocated.
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*/
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FreeExecutorState(estate);
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/* Reset queryDesc fields that no longer point to anything */
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queryDesc->tupDesc = NULL;
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queryDesc->estate = NULL;
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queryDesc->planstate = NULL;
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}
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/* ----------------------------------------------------------------
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* ExecutorRewind
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*
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* This routine may be called on an open queryDesc to rewind it
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* to the start.
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* ----------------------------------------------------------------
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*/
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void
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ExecutorRewind(QueryDesc *queryDesc)
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{
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EState *estate;
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MemoryContext oldcontext;
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/* sanity checks */
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Assert(queryDesc != NULL);
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estate = queryDesc->estate;
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Assert(estate != NULL);
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/* It's probably not sensible to rescan updating queries */
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Assert(queryDesc->operation == CMD_SELECT);
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/*
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* Switch into per-query memory context
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*/
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oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
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/*
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* rescan plan
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*/
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ExecReScan(queryDesc->planstate, NULL);
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MemoryContextSwitchTo(oldcontext);
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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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void
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ExecCheckRTPerms(List *rangeTable)
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{
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ListCell *l;
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foreach(l, rangeTable)
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{
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RangeTblEntry *rte = lfirst(l);
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ExecCheckRTEPerms(rte);
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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)
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{
|
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AclMode requiredPerms;
|
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Oid relOid;
|
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Oid userid;
|
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|
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/*
|
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* Only plain-relation RTEs need to be checked here. Subquery RTEs are
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* checked by ExecInitSubqueryScan if the subquery is still a separate
|
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* subquery --- if it's been pulled up into our query level then the RTEs
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* are in our rangetable and will be checked here. Function RTEs are
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* checked by init_fcache when the function is prepared for execution.
|
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* Join and special RTEs need no checks.
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*/
|
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if (rte->rtekind != RTE_RELATION)
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return;
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|
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/*
|
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* No work if requiredPerms is empty.
|
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*/
|
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requiredPerms = rte->requiredPerms;
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if (requiredPerms == 0)
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return;
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|
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relOid = rte->relid;
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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 in
|
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* calling it separately for each RTE. If that stops being true, we could
|
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* call it once in ExecCheckRTPerms and pass the userid down from there.
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* 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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|
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/*
|
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* We must have *all* the requiredPerms bits, so use aclmask not aclcheck.
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*/
|
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if (pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL)
|
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!= requiredPerms)
|
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aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
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get_rel_name(relOid));
|
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}
|
|
|
|
/*
|
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* Check that the query does not imply any writes to non-temp tables.
|
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*/
|
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static void
|
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ExecCheckXactReadOnly(Query *parsetree)
|
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{
|
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ListCell *l;
|
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|
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/*
|
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* CREATE TABLE AS or SELECT INTO?
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*
|
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* XXX should we allow this if the destination is temp?
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*/
|
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if (parsetree->into != NULL)
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goto fail;
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|
|
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/* Fail if write permissions are requested on any non-temp table */
|
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foreach(l, parsetree->rtable)
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{
|
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RangeTblEntry *rte = lfirst(l);
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|
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if (rte->rtekind == RTE_SUBQUERY)
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{
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ExecCheckXactReadOnly(rte->subquery);
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continue;
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}
|
|
|
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if (rte->rtekind != RTE_RELATION)
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continue;
|
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|
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if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
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continue;
|
|
|
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if (isTempNamespace(get_rel_namespace(rte->relid)))
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continue;
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|
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goto fail;
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}
|
|
|
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return;
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|
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fail:
|
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ereport(ERROR,
|
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(errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
|
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errmsg("transaction is read-only")));
|
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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
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
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InitPlan(QueryDesc *queryDesc, int eflags)
|
|
{
|
|
CmdType operation = queryDesc->operation;
|
|
Query *parseTree = queryDesc->parsetree;
|
|
Plan *plan = queryDesc->plantree;
|
|
EState *estate = queryDesc->estate;
|
|
PlanState *planstate;
|
|
List *rangeTable;
|
|
TupleDesc tupType;
|
|
ListCell *l;
|
|
|
|
/*
|
|
* Do permissions checks. It's sufficient to examine the query's top
|
|
* rangetable here --- subplan RTEs will be checked during
|
|
* ExecInitSubPlan().
|
|
*/
|
|
ExecCheckRTPerms(parseTree->rtable);
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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 = list_length(resultRelations);
|
|
resultRelInfos = (ResultRelInfo *)
|
|
palloc(numResultRelations * sizeof(ResultRelInfo));
|
|
resultRelInfo = resultRelInfos;
|
|
foreach(l, resultRelations)
|
|
{
|
|
initResultRelInfo(resultRelInfo,
|
|
lfirst_int(l),
|
|
rangeTable,
|
|
operation,
|
|
estate->es_instrument);
|
|
resultRelInfo++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Single result relation identified by parseTree->resultRelation
|
|
*/
|
|
numResultRelations = 1;
|
|
resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
|
|
initResultRelInfo(resultRelInfos,
|
|
parseTree->resultRelation,
|
|
rangeTable,
|
|
operation,
|
|
estate->es_instrument);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Detect whether we're doing SELECT INTO. If so, set the es_into_oids
|
|
* flag appropriately so that the plan tree will be initialized with the
|
|
* correct tuple descriptors. (Other SELECT INTO stuff comes later.)
|
|
*/
|
|
estate->es_select_into = false;
|
|
if (operation == CMD_SELECT && parseTree->into != NULL)
|
|
{
|
|
estate->es_select_into = true;
|
|
estate->es_into_oids = interpretOidsOption(parseTree->intoOptions);
|
|
}
|
|
|
|
/*
|
|
* Have to lock relations selected FOR UPDATE/FOR SHARE
|
|
*/
|
|
estate->es_rowMarks = NIL;
|
|
foreach(l, parseTree->rowMarks)
|
|
{
|
|
RowMarkClause *rc = (RowMarkClause *) lfirst(l);
|
|
Oid relid = getrelid(rc->rti, rangeTable);
|
|
Relation relation;
|
|
ExecRowMark *erm;
|
|
|
|
relation = heap_open(relid, RowShareLock);
|
|
erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
|
|
erm->relation = relation;
|
|
erm->rti = rc->rti;
|
|
erm->forUpdate = rc->forUpdate;
|
|
erm->noWait = rc->noWait;
|
|
snprintf(erm->resname, sizeof(erm->resname), "ctid%u", rc->rti);
|
|
estate->es_rowMarks = lappend(estate->es_rowMarks, 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. Also, if it's not a SELECT, set up a slot for use for
|
|
* trigger output tuples.
|
|
*/
|
|
{
|
|
int nSlots = ExecCountSlotsNode(plan);
|
|
|
|
if (parseTree->resultRelations != NIL)
|
|
nSlots += list_length(parseTree->resultRelations);
|
|
else
|
|
nSlots += 1;
|
|
if (operation != CMD_SELECT)
|
|
nSlots++; /* for es_trig_tuple_slot */
|
|
if (parseTree->returningLists)
|
|
nSlots++; /* for RETURNING projection */
|
|
|
|
estate->es_tupleTable = ExecCreateTupleTable(nSlots);
|
|
|
|
if (operation != CMD_SELECT)
|
|
estate->es_trig_tuple_slot =
|
|
ExecAllocTableSlot(estate->es_tupleTable);
|
|
}
|
|
|
|
/* mark EvalPlanQual not active */
|
|
estate->es_topPlan = plan;
|
|
estate->es_evalPlanQual = NULL;
|
|
estate->es_evTupleNull = NULL;
|
|
estate->es_evTuple = 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.
|
|
*/
|
|
planstate = ExecInitNode(plan, estate, eflags);
|
|
|
|
/*
|
|
* Get the tuple descriptor describing the type of tuples to return. (this
|
|
* is especially important if we are creating a relation with "SELECT
|
|
* INTO")
|
|
*/
|
|
tupType = ExecGetResultType(planstate);
|
|
|
|
/*
|
|
* Initialize the junk filter if needed. SELECT and INSERT queries need a
|
|
* filter if there are any junk attrs in the tlist. INSERT and SELECT
|
|
* INTO also need a filter if the plan may return raw disk tuples (else
|
|
* heap_insert will be scribbling on the source relation!). UPDATE and
|
|
* DELETE always need a filter, since there's always a junk 'ctid'
|
|
* attribute present --- no need to look first.
|
|
*/
|
|
{
|
|
bool junk_filter_needed = false;
|
|
ListCell *tlist;
|
|
|
|
switch (operation)
|
|
{
|
|
case CMD_SELECT:
|
|
case CMD_INSERT:
|
|
foreach(tlist, plan->targetlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tlist);
|
|
|
|
if (tle->resjunk)
|
|
{
|
|
junk_filter_needed = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!junk_filter_needed &&
|
|
(operation == CMD_INSERT || estate->es_select_into) &&
|
|
ExecMayReturnRawTuples(planstate))
|
|
junk_filter_needed = true;
|
|
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)
|
|
{
|
|
PlanState **appendplans;
|
|
int as_nplans;
|
|
ResultRelInfo *resultRelInfo;
|
|
int i;
|
|
|
|
/* Top plan had better be an Append here. */
|
|
Assert(IsA(plan, Append));
|
|
Assert(((Append *) plan)->isTarget);
|
|
Assert(IsA(planstate, AppendState));
|
|
appendplans = ((AppendState *) planstate)->appendplans;
|
|
as_nplans = ((AppendState *) planstate)->as_nplans;
|
|
Assert(as_nplans == estate->es_num_result_relations);
|
|
resultRelInfo = estate->es_result_relations;
|
|
for (i = 0; i < as_nplans; i++)
|
|
{
|
|
PlanState *subplan = appendplans[i];
|
|
JunkFilter *j;
|
|
|
|
j = ExecInitJunkFilter(subplan->plan->targetlist,
|
|
resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
|
|
ExecAllocTableSlot(estate->es_tupleTable));
|
|
resultRelInfo->ri_junkFilter = j;
|
|
resultRelInfo++;
|
|
}
|
|
|
|
/*
|
|
* 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(planstate->plan->targetlist,
|
|
tupType->tdhasoid,
|
|
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 RETURNING projections if needed.
|
|
*/
|
|
if (parseTree->returningLists)
|
|
{
|
|
TupleTableSlot *slot;
|
|
ExprContext *econtext;
|
|
ResultRelInfo *resultRelInfo;
|
|
|
|
/*
|
|
* We set QueryDesc.tupDesc to be the RETURNING rowtype in this case.
|
|
* We assume all the sublists will generate the same output tupdesc.
|
|
*/
|
|
tupType = ExecTypeFromTL((List *) linitial(parseTree->returningLists),
|
|
false);
|
|
|
|
/* Set up a slot for the output of the RETURNING projection(s) */
|
|
slot = ExecAllocTableSlot(estate->es_tupleTable);
|
|
ExecSetSlotDescriptor(slot, tupType);
|
|
/* Need an econtext too */
|
|
econtext = CreateExprContext(estate);
|
|
|
|
/*
|
|
* Build a projection for each result rel. Note that any SubPlans in
|
|
* the RETURNING lists get attached to the topmost plan node.
|
|
*/
|
|
Assert(list_length(parseTree->returningLists) == estate->es_num_result_relations);
|
|
resultRelInfo = estate->es_result_relations;
|
|
foreach(l, parseTree->returningLists)
|
|
{
|
|
List *rlist = (List *) lfirst(l);
|
|
List *rliststate;
|
|
|
|
rliststate = (List *) ExecInitExpr((Expr *) rlist, planstate);
|
|
resultRelInfo->ri_projectReturning =
|
|
ExecBuildProjectionInfo(rliststate, econtext, slot);
|
|
resultRelInfo++;
|
|
}
|
|
|
|
/*
|
|
* Because we already ran ExecInitNode() for the top plan node, any
|
|
* subplans we just attached to it won't have been initialized; so we
|
|
* have to do it here. (Ugly, but the alternatives seem worse.)
|
|
*/
|
|
foreach(l, planstate->subPlan)
|
|
{
|
|
SubPlanState *sstate = (SubPlanState *) lfirst(l);
|
|
|
|
Assert(IsA(sstate, SubPlanState));
|
|
if (sstate->planstate == NULL) /* already inited? */
|
|
ExecInitSubPlan(sstate, estate, eflags);
|
|
}
|
|
}
|
|
|
|
queryDesc->tupDesc = tupType;
|
|
queryDesc->planstate = planstate;
|
|
|
|
/*
|
|
* If doing SELECT INTO, initialize the "into" relation. We must wait
|
|
* till now so we have the "clean" result tuple type to create the new
|
|
* table from.
|
|
*
|
|
* If EXPLAIN, skip creating the "into" relation.
|
|
*/
|
|
if (estate->es_select_into && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
|
|
OpenIntoRel(queryDesc);
|
|
}
|
|
|
|
/*
|
|
* Initialize ResultRelInfo data for one result relation
|
|
*/
|
|
static void
|
|
initResultRelInfo(ResultRelInfo *resultRelInfo,
|
|
Index resultRelationIndex,
|
|
List *rangeTable,
|
|
CmdType operation,
|
|
bool doInstrument)
|
|
{
|
|
Oid resultRelationOid;
|
|
Relation resultRelationDesc;
|
|
|
|
resultRelationOid = getrelid(resultRelationIndex, rangeTable);
|
|
resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
|
|
|
|
switch (resultRelationDesc->rd_rel->relkind)
|
|
{
|
|
case RELKIND_SEQUENCE:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("cannot change sequence \"%s\"",
|
|
RelationGetRelationName(resultRelationDesc))));
|
|
break;
|
|
case RELKIND_TOASTVALUE:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("cannot change TOAST relation \"%s\"",
|
|
RelationGetRelationName(resultRelationDesc))));
|
|
break;
|
|
case RELKIND_VIEW:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("cannot change view \"%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;
|
|
/* make a copy so as not to depend on relcache info not changing... */
|
|
resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
|
|
if (resultRelInfo->ri_TrigDesc)
|
|
{
|
|
int n = resultRelInfo->ri_TrigDesc->numtriggers;
|
|
|
|
resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
|
|
palloc0(n * sizeof(FmgrInfo));
|
|
if (doInstrument)
|
|
resultRelInfo->ri_TrigInstrument = InstrAlloc(n);
|
|
else
|
|
resultRelInfo->ri_TrigInstrument = NULL;
|
|
}
|
|
else
|
|
{
|
|
resultRelInfo->ri_TrigFunctions = NULL;
|
|
resultRelInfo->ri_TrigInstrument = NULL;
|
|
}
|
|
resultRelInfo->ri_ConstraintExprs = NULL;
|
|
resultRelInfo->ri_junkFilter = NULL;
|
|
resultRelInfo->ri_projectReturning = 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);
|
|
}
|
|
|
|
/*
|
|
* ExecContextForcesOids
|
|
*
|
|
* This is pretty grotty: when doing INSERT, UPDATE, or SELECT INTO,
|
|
* we need to ensure that result tuples have space for an OID iff they are
|
|
* going to be stored into a relation that has OIDs. In other contexts
|
|
* we are free to choose whether to leave space for OIDs in result tuples
|
|
* (we generally don't want to, but we do if a physical-tlist optimization
|
|
* is possible). This routine checks the plan context and returns TRUE if the
|
|
* choice is forced, FALSE if the choice is not forced. In the TRUE case,
|
|
* *hasoids is set to the required value.
|
|
*
|
|
* One reason this is ugly is that all plan nodes in the plan tree will emit
|
|
* tuples with space for an OID, though we really only need the topmost node
|
|
* to do so. However, node types like Sort don't project new tuples but just
|
|
* return their inputs, and in those cases the requirement propagates down
|
|
* to the input node. Eventually we might make this code smart enough to
|
|
* recognize how far down the requirement really goes, but for now we just
|
|
* make all plan nodes do the same thing if the top level forces the choice.
|
|
*
|
|
* We assume that estate->es_result_relation_info is already set up to
|
|
* describe the target relation. Note that in an UPDATE that spans an
|
|
* inheritance tree, some of the target relations may have OIDs and some not.
|
|
* We have to make the decisions on a per-relation basis as we initialize
|
|
* each of the child plans of the topmost Append plan.
|
|
*
|
|
* SELECT INTO is even uglier, because we don't have the INTO relation's
|
|
* descriptor available when this code runs; we have to look aside at a
|
|
* flag set by InitPlan().
|
|
*/
|
|
bool
|
|
ExecContextForcesOids(PlanState *planstate, bool *hasoids)
|
|
{
|
|
if (planstate->state->es_select_into)
|
|
{
|
|
*hasoids = planstate->state->es_into_oids;
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
ResultRelInfo *ri = planstate->state->es_result_relation_info;
|
|
|
|
if (ri != NULL)
|
|
{
|
|
Relation rel = ri->ri_RelationDesc;
|
|
|
|
if (rel != NULL)
|
|
{
|
|
*hasoids = rel->rd_rel->relhasoids;
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecEndPlan
|
|
*
|
|
* Cleans up the query plan -- closes files and frees up storage
|
|
*
|
|
* NOTE: we are no longer very worried about freeing storage per se
|
|
* in this code; FreeExecutorState should be guaranteed to release all
|
|
* memory that needs to be released. What we are worried about doing
|
|
* is closing relations and dropping buffer pins. Thus, for example,
|
|
* tuple tables must be cleared or dropped to ensure pins are released.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
void
|
|
ExecEndPlan(PlanState *planstate, EState *estate)
|
|
{
|
|
ResultRelInfo *resultRelInfo;
|
|
int i;
|
|
ListCell *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(planstate);
|
|
|
|
/*
|
|
* 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 any relations selected FOR UPDATE/FOR SHARE, again keeping locks
|
|
*/
|
|
foreach(l, estate->es_rowMarks)
|
|
{
|
|
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 numberTuples is 0
|
|
*
|
|
* result is either a slot containing the last tuple in the case
|
|
* of a SELECT 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,
|
|
PlanState *planstate,
|
|
CmdType operation,
|
|
long numberTuples,
|
|
ScanDirection direction,
|
|
DestReceiver *dest)
|
|
{
|
|
JunkFilter *junkfilter;
|
|
TupleTableSlot *planSlot;
|
|
TupleTableSlot *slot;
|
|
ItemPointer tupleid = NULL;
|
|
ItemPointerData tuple_ctid;
|
|
long current_tuple_count;
|
|
TupleTableSlot *result;
|
|
|
|
/*
|
|
* initialize local variables
|
|
*/
|
|
current_tuple_count = 0;
|
|
result = NULL;
|
|
|
|
/*
|
|
* Set the direction.
|
|
*/
|
|
estate->es_direction = direction;
|
|
|
|
/*
|
|
* Process BEFORE EACH STATEMENT triggers
|
|
*/
|
|
switch (operation)
|
|
{
|
|
case CMD_UPDATE:
|
|
ExecBSUpdateTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
case CMD_DELETE:
|
|
ExecBSDeleteTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
case CMD_INSERT:
|
|
ExecBSInsertTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
default:
|
|
/* do nothing */
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*/
|
|
lnext: ;
|
|
if (estate->es_useEvalPlan)
|
|
{
|
|
planSlot = EvalPlanQualNext(estate);
|
|
if (TupIsNull(planSlot))
|
|
planSlot = ExecProcNode(planstate);
|
|
}
|
|
else
|
|
planSlot = ExecProcNode(planstate);
|
|
|
|
/*
|
|
* if the tuple is null, then we assume there is nothing more to
|
|
* process so we just return null...
|
|
*/
|
|
if (TupIsNull(planSlot))
|
|
{
|
|
result = NULL;
|
|
break;
|
|
}
|
|
slot = planSlot;
|
|
|
|
/*
|
|
* 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) != NULL)
|
|
{
|
|
Datum datum;
|
|
bool isNull;
|
|
|
|
/*
|
|
* extract the 'ctid' junk attribute.
|
|
*/
|
|
if (operation == CMD_UPDATE || operation == CMD_DELETE)
|
|
{
|
|
if (!ExecGetJunkAttribute(junkfilter,
|
|
slot,
|
|
"ctid",
|
|
&datum,
|
|
&isNull))
|
|
elog(ERROR, "could not find junk ctid column");
|
|
|
|
/* shouldn't ever get a null result... */
|
|
if (isNull)
|
|
elog(ERROR, "ctid is NULL");
|
|
|
|
tupleid = (ItemPointer) DatumGetPointer(datum);
|
|
tuple_ctid = *tupleid; /* make sure we don't free the ctid!! */
|
|
tupleid = &tuple_ctid;
|
|
}
|
|
|
|
/*
|
|
* Process any FOR UPDATE or FOR SHARE locking requested.
|
|
*/
|
|
else if (estate->es_rowMarks != NIL)
|
|
{
|
|
ListCell *l;
|
|
|
|
lmark: ;
|
|
foreach(l, estate->es_rowMarks)
|
|
{
|
|
ExecRowMark *erm = lfirst(l);
|
|
HeapTupleData tuple;
|
|
Buffer buffer;
|
|
ItemPointerData update_ctid;
|
|
TransactionId update_xmax;
|
|
TupleTableSlot *newSlot;
|
|
LockTupleMode lockmode;
|
|
HTSU_Result test;
|
|
|
|
if (!ExecGetJunkAttribute(junkfilter,
|
|
slot,
|
|
erm->resname,
|
|
&datum,
|
|
&isNull))
|
|
elog(ERROR, "could not find junk \"%s\" column",
|
|
erm->resname);
|
|
|
|
/* shouldn't ever get a null result... */
|
|
if (isNull)
|
|
elog(ERROR, "\"%s\" is NULL", erm->resname);
|
|
|
|
tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
|
|
|
|
if (erm->forUpdate)
|
|
lockmode = LockTupleExclusive;
|
|
else
|
|
lockmode = LockTupleShared;
|
|
|
|
test = heap_lock_tuple(erm->relation, &tuple, &buffer,
|
|
&update_ctid, &update_xmax,
|
|
estate->es_snapshot->curcid,
|
|
lockmode, erm->noWait);
|
|
ReleaseBuffer(buffer);
|
|
switch (test)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* treat it as deleted; do not process */
|
|
goto lnext;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (IsXactIsoLevelSerializable)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
|
|
errmsg("could not serialize access due to concurrent update")));
|
|
if (!ItemPointerEquals(&update_ctid,
|
|
&tuple.t_self))
|
|
{
|
|
/* updated, so look at updated version */
|
|
newSlot = EvalPlanQual(estate,
|
|
erm->rti,
|
|
&update_ctid,
|
|
update_xmax,
|
|
estate->es_snapshot->curcid);
|
|
if (!TupIsNull(newSlot))
|
|
{
|
|
slot = planSlot = 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, "unrecognized heap_lock_tuple status: %u",
|
|
test);
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a new "clean" tuple with all junk attributes removed. We
|
|
* don't need to do this for DELETE, however (there will in fact
|
|
* be no non-junk attributes in a DELETE!)
|
|
*/
|
|
if (operation != CMD_DELETE)
|
|
slot = ExecFilterJunk(junkfilter, slot);
|
|
}
|
|
|
|
/*
|
|
* 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:
|
|
ExecSelect(slot, dest, estate);
|
|
result = slot;
|
|
break;
|
|
|
|
case CMD_INSERT:
|
|
ExecInsert(slot, tupleid, planSlot, dest, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
case CMD_DELETE:
|
|
ExecDelete(tupleid, planSlot, dest, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
case CMD_UPDATE:
|
|
ExecUpdate(slot, tupleid, planSlot, dest, estate);
|
|
result = NULL;
|
|
break;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized operation code: %d",
|
|
(int) operation);
|
|
result = NULL;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* check our tuple count.. if we've processed the proper number then
|
|
* quit, else loop again and process more tuples. Zero numberTuples
|
|
* means no limit.
|
|
*/
|
|
current_tuple_count++;
|
|
if (numberTuples && numberTuples == current_tuple_count)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Process AFTER EACH STATEMENT triggers
|
|
*/
|
|
switch (operation)
|
|
{
|
|
case CMD_UPDATE:
|
|
ExecASUpdateTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
case CMD_DELETE:
|
|
ExecASDeleteTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
case CMD_INSERT:
|
|
ExecASInsertTriggers(estate, estate->es_result_relation_info);
|
|
break;
|
|
default:
|
|
/* do nothing */
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* here, result is either a slot containing a tuple in the case of a
|
|
* SELECT or NULL otherwise.
|
|
*/
|
|
return result;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecSelect
|
|
*
|
|
* SELECTs are easy.. we just pass the tuple to the appropriate
|
|
* output function.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecSelect(TupleTableSlot *slot,
|
|
DestReceiver *dest,
|
|
EState *estate)
|
|
{
|
|
(*dest->receiveSlot) (slot, dest);
|
|
IncrRetrieved();
|
|
(estate->es_processed)++;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecInsert
|
|
*
|
|
* INSERTs are trickier.. we have to insert the tuple into
|
|
* the base relation and insert appropriate tuples into the
|
|
* index relations.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecInsert(TupleTableSlot *slot,
|
|
ItemPointer tupleid,
|
|
TupleTableSlot *planSlot,
|
|
DestReceiver *dest,
|
|
EState *estate)
|
|
{
|
|
HeapTuple tuple;
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
Oid newId;
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot, making sure we have a
|
|
* writable copy
|
|
*/
|
|
tuple = ExecMaterializeSlot(slot);
|
|
|
|
/*
|
|
* 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) */
|
|
{
|
|
/*
|
|
* Put the modified tuple into a slot for convenience of routines
|
|
* below. We assume the tuple was allocated in per-tuple memory
|
|
* context, and therefore will go away by itself. The tuple table
|
|
* slot should not try to clear it.
|
|
*/
|
|
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
|
|
|
|
if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
|
|
ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
|
|
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
|
|
slot = newslot;
|
|
tuple = newtuple;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check the constraints of the tuple
|
|
*/
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints(resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* insert the tuple
|
|
*
|
|
* Note: heap_insert returns the tid (location) of the new tuple in the
|
|
* t_self field.
|
|
*/
|
|
newId = heap_insert(resultRelationDesc, tuple,
|
|
estate->es_snapshot->curcid,
|
|
true, true);
|
|
|
|
IncrAppended();
|
|
(estate->es_processed)++;
|
|
estate->es_lastoid = newId;
|
|
setLastTid(&(tuple->t_self));
|
|
|
|
/*
|
|
* insert index entries for tuple
|
|
*/
|
|
if (resultRelInfo->ri_NumIndices > 0)
|
|
ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
|
|
|
|
/* AFTER ROW INSERT Triggers */
|
|
ExecARInsertTriggers(estate, resultRelInfo, tuple);
|
|
|
|
/* Process RETURNING if present */
|
|
if (resultRelInfo->ri_projectReturning)
|
|
ExecProcessReturning(resultRelInfo->ri_projectReturning,
|
|
slot, planSlot, dest);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecDelete
|
|
*
|
|
* DELETE is like UPDATE, except that we delete the tuple and no
|
|
* index modifications are needed
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecDelete(ItemPointer tupleid,
|
|
TupleTableSlot *planSlot,
|
|
DestReceiver *dest,
|
|
EState *estate)
|
|
{
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
HTSU_Result result;
|
|
ItemPointerData update_ctid;
|
|
TransactionId update_xmax;
|
|
|
|
/*
|
|
* 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,
|
|
estate->es_snapshot->curcid);
|
|
|
|
if (!dodelete) /* "do nothing" */
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* delete the tuple
|
|
*
|
|
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
|
|
* the row to be deleted is visible to that snapshot, and throw a can't-
|
|
* serialize error if not. This is a special-case behavior needed for
|
|
* referential integrity updates in serializable transactions.
|
|
*/
|
|
ldelete:;
|
|
result = heap_delete(resultRelationDesc, tupleid,
|
|
&update_ctid, &update_xmax,
|
|
estate->es_snapshot->curcid,
|
|
estate->es_crosscheck_snapshot,
|
|
true /* wait for commit */ );
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* already deleted by self; nothing to do */
|
|
return;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (IsXactIsoLevelSerializable)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
|
|
errmsg("could not serialize access due to concurrent update")));
|
|
else if (!ItemPointerEquals(tupleid, &update_ctid))
|
|
{
|
|
TupleTableSlot *epqslot;
|
|
|
|
epqslot = EvalPlanQual(estate,
|
|
resultRelInfo->ri_RangeTableIndex,
|
|
&update_ctid,
|
|
update_xmax,
|
|
estate->es_snapshot->curcid);
|
|
if (!TupIsNull(epqslot))
|
|
{
|
|
*tupleid = update_ctid;
|
|
goto ldelete;
|
|
}
|
|
}
|
|
/* tuple already deleted; nothing to do */
|
|
return;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized heap_delete status: %u", 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 VACUUM will
|
|
* take care of it later. We can't delete index tuples immediately
|
|
* anyway, since the tuple is still visible to other transactions.
|
|
*/
|
|
|
|
/* AFTER ROW DELETE Triggers */
|
|
ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
|
|
|
|
/* Process RETURNING if present */
|
|
if (resultRelInfo->ri_projectReturning)
|
|
{
|
|
/*
|
|
* We have to put the target tuple into a slot, which means first we
|
|
* gotta fetch it. We can use the trigger tuple slot.
|
|
*/
|
|
TupleTableSlot *slot = estate->es_trig_tuple_slot;
|
|
HeapTupleData deltuple;
|
|
Buffer delbuffer;
|
|
|
|
deltuple.t_self = *tupleid;
|
|
if (!heap_fetch(resultRelationDesc, SnapshotAny,
|
|
&deltuple, &delbuffer, false, NULL))
|
|
elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
|
|
|
|
if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
|
|
ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
|
|
ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
|
|
|
|
ExecProcessReturning(resultRelInfo->ri_projectReturning,
|
|
slot, planSlot, dest);
|
|
|
|
ExecClearTuple(slot);
|
|
ReleaseBuffer(delbuffer);
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecUpdate
|
|
*
|
|
* note: we can't run UPDATE queries with transactions
|
|
* off because UPDATEs are actually INSERTs and our
|
|
* scan will mistakenly loop forever, updating the tuple
|
|
* it just inserted.. 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
|
|
ExecUpdate(TupleTableSlot *slot,
|
|
ItemPointer tupleid,
|
|
TupleTableSlot *planSlot,
|
|
DestReceiver *dest,
|
|
EState *estate)
|
|
{
|
|
HeapTuple tuple;
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
HTSU_Result result;
|
|
ItemPointerData update_ctid;
|
|
TransactionId update_xmax;
|
|
|
|
/*
|
|
* abort the operation if not running transactions
|
|
*/
|
|
if (IsBootstrapProcessingMode())
|
|
elog(ERROR, "cannot UPDATE during bootstrap");
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot, making sure we have a
|
|
* writable copy
|
|
*/
|
|
tuple = ExecMaterializeSlot(slot);
|
|
|
|
/*
|
|
* 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,
|
|
estate->es_snapshot->curcid);
|
|
|
|
if (newtuple == NULL) /* "do nothing" */
|
|
return;
|
|
|
|
if (newtuple != tuple) /* modified by Trigger(s) */
|
|
{
|
|
/*
|
|
* Put the modified tuple into a slot for convenience of routines
|
|
* below. We assume the tuple was allocated in per-tuple memory
|
|
* context, and therefore will go away by itself. The tuple table
|
|
* slot should not try to clear it.
|
|
*/
|
|
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
|
|
|
|
if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
|
|
ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
|
|
ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
|
|
slot = newslot;
|
|
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 heap_lock_tuple to lock the correct tuple, so there's no
|
|
* need to do them again.)
|
|
*/
|
|
lreplace:;
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints(resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* replace the heap tuple
|
|
*
|
|
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
|
|
* the row to be updated is visible to that snapshot, and throw a can't-
|
|
* serialize error if not. This is a special-case behavior needed for
|
|
* referential integrity updates in serializable transactions.
|
|
*/
|
|
result = heap_update(resultRelationDesc, tupleid, tuple,
|
|
&update_ctid, &update_xmax,
|
|
estate->es_snapshot->curcid,
|
|
estate->es_crosscheck_snapshot,
|
|
true /* wait for commit */ );
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* already deleted by self; nothing to do */
|
|
return;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (IsXactIsoLevelSerializable)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
|
|
errmsg("could not serialize access due to concurrent update")));
|
|
else if (!ItemPointerEquals(tupleid, &update_ctid))
|
|
{
|
|
TupleTableSlot *epqslot;
|
|
|
|
epqslot = EvalPlanQual(estate,
|
|
resultRelInfo->ri_RangeTableIndex,
|
|
&update_ctid,
|
|
update_xmax,
|
|
estate->es_snapshot->curcid);
|
|
if (!TupIsNull(epqslot))
|
|
{
|
|
*tupleid = update_ctid;
|
|
slot = ExecFilterJunk(estate->es_junkFilter, epqslot);
|
|
tuple = ExecMaterializeSlot(slot);
|
|
goto lreplace;
|
|
}
|
|
}
|
|
/* tuple already deleted; nothing to do */
|
|
return;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized heap_update status: %u", 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 UPDATEs are actually DELETEs and INSERTs, and index tuple
|
|
* deletion is done later by VACUUM (see notes in ExecDelete). All we do
|
|
* here is insert new index tuples. -cim 9/27/89
|
|
*/
|
|
|
|
/*
|
|
* insert index entries for tuple
|
|
*
|
|
* Note: heap_update returns the tid (location) of the new tuple in the
|
|
* t_self field.
|
|
*/
|
|
if (resultRelInfo->ri_NumIndices > 0)
|
|
ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
|
|
|
|
/* AFTER ROW UPDATE Triggers */
|
|
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
|
|
|
|
/* Process RETURNING if present */
|
|
if (resultRelInfo->ri_projectReturning)
|
|
ExecProcessReturning(resultRelInfo->ri_projectReturning,
|
|
slot, planSlot, dest);
|
|
}
|
|
|
|
/*
|
|
* ExecRelCheck --- check that tuple meets constraints for result relation
|
|
*/
|
|
static const char *
|
|
ExecRelCheck(ResultRelInfo *resultRelInfo,
|
|
TupleTableSlot *slot, EState *estate)
|
|
{
|
|
Relation rel = resultRelInfo->ri_RelationDesc;
|
|
int ncheck = rel->rd_att->constr->num_check;
|
|
ConstrCheck *check = rel->rd_att->constr->check;
|
|
ExprContext *econtext;
|
|
MemoryContext oldContext;
|
|
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++)
|
|
{
|
|
/* ExecQual wants implicit-AND form */
|
|
qual = make_ands_implicit(stringToNode(check[i].ccbin));
|
|
resultRelInfo->ri_ConstraintExprs[i] = (List *)
|
|
ExecPrepareExpr((Expr *) qual, estate);
|
|
}
|
|
MemoryContextSwitchTo(oldContext);
|
|
}
|
|
|
|
/*
|
|
* We will use the EState's per-tuple context for evaluating constraint
|
|
* expressions (creating it if it's not already there).
|
|
*/
|
|
econtext = GetPerTupleExprContext(estate);
|
|
|
|
/* Arrange for econtext's scan tuple to be the tuple under test */
|
|
econtext->ecxt_scantuple = slot;
|
|
|
|
/* And evaluate the constraints */
|
|
for (i = 0; i < ncheck; i++)
|
|
{
|
|
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 NULL;
|
|
}
|
|
|
|
void
|
|
ExecConstraints(ResultRelInfo *resultRelInfo,
|
|
TupleTableSlot *slot, EState *estate)
|
|
{
|
|
Relation rel = resultRelInfo->ri_RelationDesc;
|
|
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 &&
|
|
slot_attisnull(slot, attrChk))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_NOT_NULL_VIOLATION),
|
|
errmsg("null value in column \"%s\" violates not-null constraint",
|
|
NameStr(rel->rd_att->attrs[attrChk - 1]->attname))));
|
|
}
|
|
}
|
|
|
|
if (constr->num_check > 0)
|
|
{
|
|
const char *failed;
|
|
|
|
if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_CHECK_VIOLATION),
|
|
errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
|
|
RelationGetRelationName(rel), failed)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ExecProcessReturning --- evaluate a RETURNING list and send to dest
|
|
*
|
|
* projectReturning: RETURNING projection info for current result rel
|
|
* tupleSlot: slot holding tuple actually inserted/updated/deleted
|
|
* planSlot: slot holding tuple returned by top plan node
|
|
* dest: where to send the output
|
|
*/
|
|
static void
|
|
ExecProcessReturning(ProjectionInfo *projectReturning,
|
|
TupleTableSlot *tupleSlot,
|
|
TupleTableSlot *planSlot,
|
|
DestReceiver *dest)
|
|
{
|
|
ExprContext *econtext = projectReturning->pi_exprContext;
|
|
TupleTableSlot *retSlot;
|
|
|
|
/*
|
|
* Reset per-tuple memory context to free any expression evaluation
|
|
* storage allocated in the previous cycle.
|
|
*/
|
|
ResetExprContext(econtext);
|
|
|
|
/* Make tuple and any needed join variables available to ExecProject */
|
|
econtext->ecxt_scantuple = tupleSlot;
|
|
econtext->ecxt_outertuple = planSlot;
|
|
|
|
/* Compute the RETURNING expressions */
|
|
retSlot = ExecProject(projectReturning, NULL);
|
|
|
|
/* Send to dest */
|
|
(*dest->receiveSlot) (retSlot, dest);
|
|
|
|
ExecClearTuple(retSlot);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* estate - executor state data
|
|
* rti - rangetable index of table containing tuple
|
|
* *tid - t_ctid from the outdated tuple (ie, next updated version)
|
|
* priorXmax - t_xmax from the outdated tuple
|
|
* curCid - command ID of current command of my transaction
|
|
*
|
|
* *tid is also an output parameter: it's modified to hold the TID of the
|
|
* latest version of the tuple (note this may be changed even on failure)
|
|
*
|
|
* Returns a slot containing the new candidate update/delete tuple, or
|
|
* NULL if we determine we shouldn't process the row.
|
|
*/
|
|
TupleTableSlot *
|
|
EvalPlanQual(EState *estate, Index rti,
|
|
ItemPointer tid, TransactionId priorXmax, CommandId curCid)
|
|
{
|
|
evalPlanQual *epq;
|
|
EState *epqstate;
|
|
Relation relation;
|
|
HeapTupleData tuple;
|
|
HeapTuple copyTuple = NULL;
|
|
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
|
|
{
|
|
ListCell *l;
|
|
|
|
relation = NULL;
|
|
foreach(l, estate->es_rowMarks)
|
|
{
|
|
if (((ExecRowMark *) lfirst(l))->rti == rti)
|
|
{
|
|
relation = ((ExecRowMark *) lfirst(l))->relation;
|
|
break;
|
|
}
|
|
}
|
|
if (relation == NULL)
|
|
elog(ERROR, "could not find RowMark for RT index %u", rti);
|
|
}
|
|
|
|
/*
|
|
* fetch tid tuple
|
|
*
|
|
* Loop here to deal with updated or busy tuples
|
|
*/
|
|
tuple.t_self = *tid;
|
|
for (;;)
|
|
{
|
|
Buffer buffer;
|
|
|
|
if (heap_fetch(relation, SnapshotDirty, &tuple, &buffer, true, NULL))
|
|
{
|
|
/*
|
|
* If xmin isn't what we're expecting, the slot must have been
|
|
* recycled and reused for an unrelated tuple. This implies that
|
|
* the latest version of the row was deleted, so we need do
|
|
* nothing. (Should be safe to examine xmin without getting
|
|
* buffer's content lock, since xmin never changes in an existing
|
|
* tuple.)
|
|
*/
|
|
if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
|
|
priorXmax))
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/* otherwise xmin should not be dirty... */
|
|
if (TransactionIdIsValid(SnapshotDirty->xmin))
|
|
elog(ERROR, "t_xmin is uncommitted in tuple to be updated");
|
|
|
|
/*
|
|
* If tuple is being updated by other transaction then we have to
|
|
* wait for its commit/abort.
|
|
*/
|
|
if (TransactionIdIsValid(SnapshotDirty->xmax))
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
XactLockTableWait(SnapshotDirty->xmax);
|
|
continue; /* loop back to repeat heap_fetch */
|
|
}
|
|
|
|
/*
|
|
* If tuple was inserted by our own transaction, we have to check
|
|
* cmin against curCid: cmin >= curCid means our command cannot
|
|
* see the tuple, so we should ignore it. Without this we are
|
|
* open to the "Halloween problem" of indefinitely re-updating the
|
|
* same tuple. (We need not check cmax because
|
|
* HeapTupleSatisfiesDirty will consider a tuple deleted by our
|
|
* transaction dead, regardless of cmax.) We just checked that
|
|
* priorXmax == xmin, so we can test that variable instead of
|
|
* doing HeapTupleHeaderGetXmin again.
|
|
*/
|
|
if (TransactionIdIsCurrentTransactionId(priorXmax) &&
|
|
HeapTupleHeaderGetCmin(tuple.t_data) >= curCid)
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* We got tuple - now copy it for use by recheck query.
|
|
*/
|
|
copyTuple = heap_copytuple(&tuple);
|
|
ReleaseBuffer(buffer);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If the referenced slot was actually empty, the latest version of
|
|
* the row must have been deleted, so we need do nothing.
|
|
*/
|
|
if (tuple.t_data == NULL)
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* As above, if xmin isn't what we're expecting, do nothing.
|
|
*/
|
|
if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
|
|
priorXmax))
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* If we get here, the tuple was found but failed SnapshotDirty.
|
|
* Assuming the xmin is either a committed xact or our own xact (as it
|
|
* certainly should be if we're trying to modify the tuple), this must
|
|
* mean that the row was updated or deleted by either a committed xact
|
|
* or our own xact. If it was deleted, we can ignore it; if it was
|
|
* updated then chain up to the next version and repeat the whole
|
|
* test.
|
|
*
|
|
* As above, it should be safe to examine xmax and t_ctid without the
|
|
* buffer content lock, because they can't be changing.
|
|
*/
|
|
if (ItemPointerEquals(&tuple.t_self, &tuple.t_data->t_ctid))
|
|
{
|
|
/* deleted, so forget about it */
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/* updated, so look at the updated row */
|
|
tuple.t_self = tuple.t_data->t_ctid;
|
|
/* updated row should have xmin matching this xmax */
|
|
priorXmax = HeapTupleHeaderGetXmax(tuple.t_data);
|
|
ReleaseBuffer(buffer);
|
|
/* loop back to fetch next in chain */
|
|
}
|
|
|
|
/*
|
|
* 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 = estate->es_evalPlanQual;
|
|
endNode = true;
|
|
|
|
if (epq != NULL && epq->rti == 0)
|
|
{
|
|
/* Top PQ stack entry is idle, so re-use it */
|
|
Assert(!(estate->es_useEvalPlan) && epq->next == 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;
|
|
|
|
/* stop execution */
|
|
EvalPlanQualStop(epq);
|
|
/* pop previous PlanQual from the stack */
|
|
oldepq = epq->next;
|
|
Assert(oldepq && oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
estate->es_evalPlanQual = 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 *) palloc0(sizeof(evalPlanQual));
|
|
newepq->free = NULL;
|
|
newepq->estate = NULL;
|
|
newepq->planstate = NULL;
|
|
}
|
|
else
|
|
{
|
|
/* recycle previously used PlanQual */
|
|
Assert(newepq->estate == NULL);
|
|
epq->free = NULL;
|
|
}
|
|
/* push current PQ to the stack */
|
|
newepq->next = epq;
|
|
epq = newepq;
|
|
estate->es_evalPlanQual = epq;
|
|
epq->rti = rti;
|
|
endNode = false;
|
|
}
|
|
|
|
Assert(epq->rti == rti);
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* Note that the stack of free evalPlanQual nodes is quite useless at the
|
|
* moment, since it only saves us from pallocing/releasing the
|
|
* evalPlanQual nodes themselves. But it will be useful once we implement
|
|
* ReScan instead of end/restart for re-using PlanQual nodes.
|
|
*/
|
|
if (endNode)
|
|
{
|
|
/* stop execution */
|
|
EvalPlanQualStop(epq);
|
|
}
|
|
|
|
/*
|
|
* Initialize new recheck query.
|
|
*
|
|
* Note: if we were re-using PlanQual plans via ExecReScan, we'd need to
|
|
* instead copy down changeable state from the top plan (including
|
|
* es_result_relation_info, es_junkFilter) and reset locally changeable
|
|
* state in the epq (including es_param_exec_vals, es_evTupleNull).
|
|
*/
|
|
EvalPlanQualStart(epq, estate, epq->next);
|
|
|
|
/*
|
|
* free old RTE' tuple, if any, and store target tuple where relation's
|
|
* scan node will see it
|
|
*/
|
|
epqstate = epq->estate;
|
|
if (epqstate->es_evTuple[rti - 1] != NULL)
|
|
heap_freetuple(epqstate->es_evTuple[rti - 1]);
|
|
epqstate->es_evTuple[rti - 1] = copyTuple;
|
|
|
|
return EvalPlanQualNext(estate);
|
|
}
|
|
|
|
static TupleTableSlot *
|
|
EvalPlanQualNext(EState *estate)
|
|
{
|
|
evalPlanQual *epq = estate->es_evalPlanQual;
|
|
MemoryContext oldcontext;
|
|
TupleTableSlot *slot;
|
|
|
|
Assert(epq->rti != 0);
|
|
|
|
lpqnext:;
|
|
oldcontext = MemoryContextSwitchTo(epq->estate->es_query_cxt);
|
|
slot = ExecProcNode(epq->planstate);
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
/*
|
|
* No more tuples for this PQ. Continue previous one.
|
|
*/
|
|
if (TupIsNull(slot))
|
|
{
|
|
evalPlanQual *oldepq;
|
|
|
|
/* stop execution */
|
|
EvalPlanQualStop(epq);
|
|
/* pop old PQ from the stack */
|
|
oldepq = epq->next;
|
|
if (oldepq == NULL)
|
|
{
|
|
/* this is the first (oldest) PQ - mark as free */
|
|
epq->rti = 0;
|
|
estate->es_useEvalPlan = false;
|
|
/* and continue Query execution */
|
|
return NULL;
|
|
}
|
|
Assert(oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
estate->es_evalPlanQual = epq;
|
|
goto lpqnext;
|
|
}
|
|
|
|
return slot;
|
|
}
|
|
|
|
static void
|
|
EndEvalPlanQual(EState *estate)
|
|
{
|
|
evalPlanQual *epq = estate->es_evalPlanQual;
|
|
|
|
if (epq->rti == 0) /* plans already shutdowned */
|
|
{
|
|
Assert(epq->next == NULL);
|
|
return;
|
|
}
|
|
|
|
for (;;)
|
|
{
|
|
evalPlanQual *oldepq;
|
|
|
|
/* stop execution */
|
|
EvalPlanQualStop(epq);
|
|
/* pop old PQ from the stack */
|
|
oldepq = epq->next;
|
|
if (oldepq == NULL)
|
|
{
|
|
/* this is the first (oldest) PQ - mark as free */
|
|
epq->rti = 0;
|
|
estate->es_useEvalPlan = false;
|
|
break;
|
|
}
|
|
Assert(oldepq->rti != 0);
|
|
/* push current PQ to freePQ stack */
|
|
oldepq->free = epq;
|
|
epq = oldepq;
|
|
estate->es_evalPlanQual = epq;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Start execution of one level of PlanQual.
|
|
*
|
|
* This is a cut-down version of ExecutorStart(): we copy some state from
|
|
* the top-level estate rather than initializing it fresh.
|
|
*/
|
|
static void
|
|
EvalPlanQualStart(evalPlanQual *epq, EState *estate, evalPlanQual *priorepq)
|
|
{
|
|
EState *epqstate;
|
|
int rtsize;
|
|
MemoryContext oldcontext;
|
|
|
|
rtsize = list_length(estate->es_range_table);
|
|
|
|
epq->estate = epqstate = CreateExecutorState();
|
|
|
|
oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
|
|
|
|
/*
|
|
* The epqstates share the top query's copy of unchanging state such as
|
|
* the snapshot, rangetable, result-rel info, and external Param info.
|
|
* They need their own copies of local state, including a tuple table,
|
|
* es_param_exec_vals, etc.
|
|
*/
|
|
epqstate->es_direction = ForwardScanDirection;
|
|
epqstate->es_snapshot = estate->es_snapshot;
|
|
epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
|
|
epqstate->es_range_table = estate->es_range_table;
|
|
epqstate->es_result_relations = estate->es_result_relations;
|
|
epqstate->es_num_result_relations = estate->es_num_result_relations;
|
|
epqstate->es_result_relation_info = estate->es_result_relation_info;
|
|
epqstate->es_junkFilter = estate->es_junkFilter;
|
|
epqstate->es_into_relation_descriptor = estate->es_into_relation_descriptor;
|
|
epqstate->es_into_relation_use_wal = estate->es_into_relation_use_wal;
|
|
epqstate->es_param_list_info = estate->es_param_list_info;
|
|
if (estate->es_topPlan->nParamExec > 0)
|
|
epqstate->es_param_exec_vals = (ParamExecData *)
|
|
palloc0(estate->es_topPlan->nParamExec * sizeof(ParamExecData));
|
|
epqstate->es_rowMarks = estate->es_rowMarks;
|
|
epqstate->es_instrument = estate->es_instrument;
|
|
epqstate->es_select_into = estate->es_select_into;
|
|
epqstate->es_into_oids = estate->es_into_oids;
|
|
epqstate->es_topPlan = estate->es_topPlan;
|
|
|
|
/*
|
|
* 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 *) palloc0(rtsize * sizeof(bool));
|
|
if (priorepq == NULL)
|
|
/* first PQ stack entry */
|
|
epqstate->es_evTuple = (HeapTuple *)
|
|
palloc0(rtsize * sizeof(HeapTuple));
|
|
else
|
|
/* later stack entries share the same storage */
|
|
epqstate->es_evTuple = priorepq->estate->es_evTuple;
|
|
|
|
epqstate->es_tupleTable =
|
|
ExecCreateTupleTable(estate->es_tupleTable->size);
|
|
|
|
epq->planstate = ExecInitNode(estate->es_topPlan, epqstate, 0);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
/*
|
|
* End execution of one level of PlanQual.
|
|
*
|
|
* This is a cut-down version of ExecutorEnd(); basically we want to do most
|
|
* of the normal cleanup, but *not* close result relations (which we are
|
|
* just sharing from the outer query).
|
|
*/
|
|
static void
|
|
EvalPlanQualStop(evalPlanQual *epq)
|
|
{
|
|
EState *epqstate = epq->estate;
|
|
MemoryContext oldcontext;
|
|
|
|
oldcontext = MemoryContextSwitchTo(epqstate->es_query_cxt);
|
|
|
|
ExecEndNode(epq->planstate);
|
|
|
|
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;
|
|
}
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
FreeExecutorState(epqstate);
|
|
|
|
epq->estate = NULL;
|
|
epq->planstate = NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Support for SELECT INTO (a/k/a CREATE TABLE AS)
|
|
*
|
|
* We implement SELECT INTO by diverting SELECT's normal output with
|
|
* a specialized DestReceiver type.
|
|
*
|
|
* TODO: remove some of the INTO-specific cruft from EState, and keep
|
|
* it in the DestReceiver instead.
|
|
*/
|
|
|
|
typedef struct
|
|
{
|
|
DestReceiver pub; /* publicly-known function pointers */
|
|
EState *estate; /* EState we are working with */
|
|
} DR_intorel;
|
|
|
|
/*
|
|
* OpenIntoRel --- actually create the SELECT INTO target relation
|
|
*
|
|
* This also replaces QueryDesc->dest with the special DestReceiver for
|
|
* SELECT INTO. We assume that the correct result tuple type has already
|
|
* been placed in queryDesc->tupDesc.
|
|
*/
|
|
static void
|
|
OpenIntoRel(QueryDesc *queryDesc)
|
|
{
|
|
Query *parseTree = queryDesc->parsetree;
|
|
EState *estate = queryDesc->estate;
|
|
Relation intoRelationDesc;
|
|
char *intoName;
|
|
Oid namespaceId;
|
|
Oid tablespaceId;
|
|
Datum reloptions;
|
|
AclResult aclresult;
|
|
Oid intoRelationId;
|
|
TupleDesc tupdesc;
|
|
DR_intorel *myState;
|
|
|
|
/*
|
|
* Check consistency of arguments
|
|
*/
|
|
if (parseTree->intoOnCommit != ONCOMMIT_NOOP && !parseTree->into->istemp)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
|
|
errmsg("ON COMMIT can only be used on temporary tables")));
|
|
|
|
/*
|
|
* Find namespace to create in, check its permissions
|
|
*/
|
|
intoName = parseTree->into->relname;
|
|
namespaceId = RangeVarGetCreationNamespace(parseTree->into);
|
|
|
|
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
|
|
ACL_CREATE);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
|
|
get_namespace_name(namespaceId));
|
|
|
|
/*
|
|
* Select tablespace to use. If not specified, use default_tablespace
|
|
* (which may in turn default to database's default).
|
|
*/
|
|
if (parseTree->intoTableSpaceName)
|
|
{
|
|
tablespaceId = get_tablespace_oid(parseTree->intoTableSpaceName);
|
|
if (!OidIsValid(tablespaceId))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("tablespace \"%s\" does not exist",
|
|
parseTree->intoTableSpaceName)));
|
|
}
|
|
else
|
|
{
|
|
tablespaceId = GetDefaultTablespace();
|
|
/* note InvalidOid is OK in this case */
|
|
}
|
|
|
|
/* Check permissions except when using the database's default space */
|
|
if (OidIsValid(tablespaceId))
|
|
{
|
|
AclResult aclresult;
|
|
|
|
aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
|
|
ACL_CREATE);
|
|
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, ACL_KIND_TABLESPACE,
|
|
get_tablespace_name(tablespaceId));
|
|
}
|
|
|
|
/* Parse and validate any reloptions */
|
|
reloptions = transformRelOptions((Datum) 0,
|
|
parseTree->intoOptions,
|
|
true,
|
|
false);
|
|
(void) heap_reloptions(RELKIND_RELATION, reloptions, true);
|
|
|
|
/* have to copy the actual tupdesc to get rid of any constraints */
|
|
tupdesc = CreateTupleDescCopy(queryDesc->tupDesc);
|
|
|
|
/* Now we can actually create the new relation */
|
|
intoRelationId = heap_create_with_catalog(intoName,
|
|
namespaceId,
|
|
tablespaceId,
|
|
InvalidOid,
|
|
GetUserId(),
|
|
tupdesc,
|
|
RELKIND_RELATION,
|
|
false,
|
|
true,
|
|
0,
|
|
parseTree->intoOnCommit,
|
|
reloptions,
|
|
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(intoRelationId);
|
|
|
|
/*
|
|
* And open the constructed table for writing.
|
|
*/
|
|
intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
|
|
|
|
/* use_wal off requires rd_targblock be initially invalid */
|
|
Assert(intoRelationDesc->rd_targblock == InvalidBlockNumber);
|
|
|
|
/*
|
|
* We can skip WAL-logging the insertions, unless PITR is in use.
|
|
*
|
|
* Note that for a non-temp INTO table, this is safe only because we know
|
|
* that the catalog changes above will have been WAL-logged, and so
|
|
* RecordTransactionCommit will think it needs to WAL-log the eventual
|
|
* transaction commit. Else the commit might be lost, even though all the
|
|
* data is safely fsync'd ...
|
|
*/
|
|
estate->es_into_relation_use_wal = XLogArchivingActive();
|
|
estate->es_into_relation_descriptor = intoRelationDesc;
|
|
|
|
/*
|
|
* Now replace the query's DestReceiver with one for SELECT INTO
|
|
*/
|
|
queryDesc->dest = CreateDestReceiver(DestIntoRel, NULL);
|
|
myState = (DR_intorel *) queryDesc->dest;
|
|
Assert(myState->pub.mydest == DestIntoRel);
|
|
myState->estate = estate;
|
|
}
|
|
|
|
/*
|
|
* CloseIntoRel --- clean up SELECT INTO at ExecutorEnd time
|
|
*/
|
|
static void
|
|
CloseIntoRel(QueryDesc *queryDesc)
|
|
{
|
|
EState *estate = queryDesc->estate;
|
|
|
|
/* OpenIntoRel might never have gotten called */
|
|
if (estate->es_into_relation_descriptor)
|
|
{
|
|
/*
|
|
* If we skipped using WAL, and it's not a temp relation, we must
|
|
* force the relation down to disk before it's safe to commit the
|
|
* transaction. This requires forcing out any dirty buffers and then
|
|
* doing a forced fsync.
|
|
*/
|
|
if (!estate->es_into_relation_use_wal &&
|
|
!estate->es_into_relation_descriptor->rd_istemp)
|
|
{
|
|
FlushRelationBuffers(estate->es_into_relation_descriptor);
|
|
/* FlushRelationBuffers will have opened rd_smgr */
|
|
smgrimmedsync(estate->es_into_relation_descriptor->rd_smgr);
|
|
}
|
|
|
|
/* close rel, but keep lock until commit */
|
|
heap_close(estate->es_into_relation_descriptor, NoLock);
|
|
|
|
estate->es_into_relation_descriptor = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* CreateIntoRelDestReceiver -- create a suitable DestReceiver object
|
|
*
|
|
* Since CreateDestReceiver doesn't accept the parameters we'd need,
|
|
* we just leave the private fields empty here. OpenIntoRel will
|
|
* fill them in.
|
|
*/
|
|
DestReceiver *
|
|
CreateIntoRelDestReceiver(void)
|
|
{
|
|
DR_intorel *self = (DR_intorel *) palloc(sizeof(DR_intorel));
|
|
|
|
self->pub.receiveSlot = intorel_receive;
|
|
self->pub.rStartup = intorel_startup;
|
|
self->pub.rShutdown = intorel_shutdown;
|
|
self->pub.rDestroy = intorel_destroy;
|
|
self->pub.mydest = DestIntoRel;
|
|
|
|
self->estate = NULL;
|
|
|
|
return (DestReceiver *) self;
|
|
}
|
|
|
|
/*
|
|
* intorel_startup --- executor startup
|
|
*/
|
|
static void
|
|
intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
|
|
{
|
|
/* no-op */
|
|
}
|
|
|
|
/*
|
|
* intorel_receive --- receive one tuple
|
|
*/
|
|
static void
|
|
intorel_receive(TupleTableSlot *slot, DestReceiver *self)
|
|
{
|
|
DR_intorel *myState = (DR_intorel *) self;
|
|
EState *estate = myState->estate;
|
|
HeapTuple tuple;
|
|
|
|
tuple = ExecCopySlotTuple(slot);
|
|
|
|
heap_insert(estate->es_into_relation_descriptor,
|
|
tuple,
|
|
estate->es_snapshot->curcid,
|
|
estate->es_into_relation_use_wal,
|
|
false); /* never any point in using FSM */
|
|
|
|
/* We know this is a newly created relation, so there are no indexes */
|
|
|
|
heap_freetuple(tuple);
|
|
|
|
IncrAppended();
|
|
}
|
|
|
|
/*
|
|
* intorel_shutdown --- executor end
|
|
*/
|
|
static void
|
|
intorel_shutdown(DestReceiver *self)
|
|
{
|
|
/* no-op */
|
|
}
|
|
|
|
/*
|
|
* intorel_destroy --- release DestReceiver object
|
|
*/
|
|
static void
|
|
intorel_destroy(DestReceiver *self)
|
|
{
|
|
pfree(self);
|
|
}
|