b8c6c71d1c
Remove bespoke code in DoCopy and RI_Initial_Check, which now instead fabricate call ExecCheckRTPerms with a manufactured RangeTblEntry. This is intended to make it feasible for an enhanced security provider to actually make use of ExecutorCheckPerms_hook, but also has the advantage that RI_Initial_Check can allow use of the fast-path when column-level but not table-level permissions are present. KaiGai Kohei. Reviewed (in an earlier version) by Stephen Frost, and by me. Some further changes to the comments by me.
2344 lines
65 KiB
C
2344 lines
65 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* The old ExecutorMain() has been replaced by ExecutorStart(),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) 1996-2010, 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 1.352 2010/07/22 00:47:52 rhaas 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/reloptions.h"
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#include "access/sysattr.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 "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/bufmgr.h"
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#include "storage/lmgr.h"
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#include "storage/smgr.h"
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#include "tcop/utility.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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#include "utils/snapmgr.h"
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#include "utils/tqual.h"
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/* Hooks for plugins to get control in ExecutorStart/Run/End() */
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ExecutorStart_hook_type ExecutorStart_hook = NULL;
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ExecutorRun_hook_type ExecutorRun_hook = NULL;
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ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
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/* Hook for plugin to get control in ExecCheckRTPerms() */
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ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
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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 ExecEndPlan(PlanState *planstate, EState *estate);
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static void ExecutePlan(EState *estate, PlanState *planstate,
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CmdType operation,
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bool sendTuples,
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long numberTuples,
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ScanDirection direction,
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DestReceiver *dest);
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static bool ExecCheckRTEPerms(RangeTblEntry *rte);
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static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
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static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
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Plan *planTree);
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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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* We provide a function hook variable that lets loadable plugins
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* get control when ExecutorStart is called. Such a plugin would
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* normally call standard_ExecutorStart().
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*
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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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if (ExecutorStart_hook)
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(*ExecutorStart_hook) (queryDesc, eflags);
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else
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standard_ExecutorStart(queryDesc, eflags);
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}
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void
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standard_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->plannedstmt);
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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 external parameters, if any, from queryDesc; and allocate
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* workspace for internal parameters
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*/
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estate->es_param_list_info = queryDesc->params;
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if (queryDesc->plannedstmt->nParamExec > 0)
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estate->es_param_exec_vals = (ParamExecData *)
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palloc0(queryDesc->plannedstmt->nParamExec * sizeof(ParamExecData));
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/*
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* If non-read-only query, set the command ID to mark output tuples with
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*/
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switch (queryDesc->operation)
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{
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case CMD_SELECT:
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/* SELECT INTO and SELECT FOR UPDATE/SHARE need to mark tuples */
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if (queryDesc->plannedstmt->intoClause != NULL ||
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queryDesc->plannedstmt->rowMarks != NIL)
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estate->es_output_cid = GetCurrentCommandId(true);
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break;
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case CMD_INSERT:
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case CMD_DELETE:
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case CMD_UPDATE:
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estate->es_output_cid = GetCurrentCommandId(true);
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break;
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default:
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elog(ERROR, "unrecognized operation code: %d",
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(int) queryDesc->operation);
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break;
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}
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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 = RegisterSnapshot(queryDesc->snapshot);
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estate->es_crosscheck_snapshot = RegisterSnapshot(queryDesc->crosscheck_snapshot);
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estate->es_instrument = queryDesc->instrument_options;
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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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* There is no return value, but output tuples (if any) are sent to
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* the destination receiver specified in the QueryDesc; and the number
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* of tuples processed at the top level can be found in
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* estate->es_processed.
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*
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* We provide a function hook variable that lets loadable plugins
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* get control when ExecutorRun is called. Such a plugin would
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* normally call standard_ExecutorRun().
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*
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* ----------------------------------------------------------------
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*/
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void
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ExecutorRun(QueryDesc *queryDesc,
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ScanDirection direction, long count)
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{
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if (ExecutorRun_hook)
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(*ExecutorRun_hook) (queryDesc, direction, count);
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else
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standard_ExecutorRun(queryDesc, direction, count);
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}
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void
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standard_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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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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/* Allow instrumentation of ExecutorRun overall runtime */
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if (queryDesc->totaltime)
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InstrStartNode(queryDesc->totaltime);
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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->plannedstmt->hasReturning);
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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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ExecutePlan(estate,
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queryDesc->planstate,
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operation,
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sendTuples,
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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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if (queryDesc->totaltime)
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InstrStopNode(queryDesc->totaltime, estate->es_processed);
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MemoryContextSwitchTo(oldcontext);
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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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* We provide a function hook variable that lets loadable plugins
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* get control when ExecutorEnd is called. Such a plugin would
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* normally call standard_ExecutorEnd().
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*
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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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if (ExecutorEnd_hook)
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(*ExecutorEnd_hook) (queryDesc);
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else
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standard_ExecutorEnd(queryDesc);
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}
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void
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standard_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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/* do away with our snapshots */
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UnregisterSnapshot(estate->es_snapshot);
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UnregisterSnapshot(estate->es_crosscheck_snapshot);
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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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queryDesc->totaltime = NULL;
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}
|
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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);
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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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* Returns true if permissions are adequate. Otherwise, throws an appropriate
|
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* error if ereport_on_violation is true, or simply returns false otherwise.
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*/
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bool
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ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation)
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{
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ListCell *l;
|
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bool result = true;
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foreach(l, rangeTable)
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{
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RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
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result = ExecCheckRTEPerms(rte);
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if (!result)
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{
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Assert(rte->rtekind == RTE_RELATION);
|
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if (ereport_on_violation)
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aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
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get_rel_name(rte->relid));
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return false;
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}
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}
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|
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if (ExecutorCheckPerms_hook)
|
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result = (*ExecutorCheckPerms_hook)(rangeTable,
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ereport_on_violation);
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return result;
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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 bool
|
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ExecCheckRTEPerms(RangeTblEntry *rte)
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{
|
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AclMode requiredPerms;
|
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AclMode relPerms;
|
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AclMode remainingPerms;
|
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Oid relOid;
|
|
Oid userid;
|
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Bitmapset *tmpset;
|
|
int col;
|
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|
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/*
|
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* Only plain-relation RTEs need to 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, subquery, and special RTEs need no checks.
|
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*/
|
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if (rte->rtekind != RTE_RELATION)
|
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return true;
|
|
|
|
/*
|
|
* No work if requiredPerms is empty.
|
|
*/
|
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requiredPerms = rte->requiredPerms;
|
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if (requiredPerms == 0)
|
|
return true;
|
|
|
|
relOid = rte->relid;
|
|
|
|
/*
|
|
* userid to check as: current user unless we have a setuid indication.
|
|
*
|
|
* 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.
|
|
*/
|
|
userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
|
|
|
|
/*
|
|
* We must have *all* the requiredPerms bits, but some of the bits can be
|
|
* satisfied from column-level rather than relation-level permissions.
|
|
* First, remove any bits that are satisfied by relation permissions.
|
|
*/
|
|
relPerms = pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL);
|
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remainingPerms = requiredPerms & ~relPerms;
|
|
if (remainingPerms != 0)
|
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{
|
|
/*
|
|
* If we lack any permissions that exist only as relation permissions,
|
|
* we can fail straight away.
|
|
*/
|
|
if (remainingPerms & ~(ACL_SELECT | ACL_INSERT | ACL_UPDATE))
|
|
return false;
|
|
|
|
/*
|
|
* Check to see if we have the needed privileges at column level.
|
|
*
|
|
* Note: failures just report a table-level error; it would be nicer
|
|
* to report a column-level error if we have some but not all of the
|
|
* column privileges.
|
|
*/
|
|
if (remainingPerms & ACL_SELECT)
|
|
{
|
|
/*
|
|
* When the query doesn't explicitly reference any columns (for
|
|
* example, SELECT COUNT(*) FROM table), allow the query if we
|
|
* have SELECT on any column of the rel, as per SQL spec.
|
|
*/
|
|
if (bms_is_empty(rte->selectedCols))
|
|
{
|
|
if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
|
|
ACLMASK_ANY) != ACLCHECK_OK)
|
|
return false;
|
|
}
|
|
|
|
tmpset = bms_copy(rte->selectedCols);
|
|
while ((col = bms_first_member(tmpset)) >= 0)
|
|
{
|
|
/* remove the column number offset */
|
|
col += FirstLowInvalidHeapAttributeNumber;
|
|
if (col == InvalidAttrNumber)
|
|
{
|
|
/* Whole-row reference, must have priv on all cols */
|
|
if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
|
|
ACLMASK_ALL) != ACLCHECK_OK)
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
if (pg_attribute_aclcheck(relOid, col, userid,
|
|
ACL_SELECT) != ACLCHECK_OK)
|
|
return false;
|
|
}
|
|
}
|
|
bms_free(tmpset);
|
|
}
|
|
|
|
/*
|
|
* Basically the same for the mod columns, with either INSERT or
|
|
* UPDATE privilege as specified by remainingPerms.
|
|
*/
|
|
remainingPerms &= ~ACL_SELECT;
|
|
if (remainingPerms != 0)
|
|
{
|
|
/*
|
|
* When the query doesn't explicitly change any columns, allow the
|
|
* query if we have permission on any column of the rel. This is
|
|
* to handle SELECT FOR UPDATE as well as possible corner cases in
|
|
* INSERT and UPDATE.
|
|
*/
|
|
if (bms_is_empty(rte->modifiedCols))
|
|
{
|
|
if (pg_attribute_aclcheck_all(relOid, userid, remainingPerms,
|
|
ACLMASK_ANY) != ACLCHECK_OK)
|
|
return false;
|
|
}
|
|
|
|
tmpset = bms_copy(rte->modifiedCols);
|
|
while ((col = bms_first_member(tmpset)) >= 0)
|
|
{
|
|
/* remove the column number offset */
|
|
col += FirstLowInvalidHeapAttributeNumber;
|
|
if (col == InvalidAttrNumber)
|
|
{
|
|
/* whole-row reference can't happen here */
|
|
elog(ERROR, "whole-row update is not implemented");
|
|
}
|
|
else
|
|
{
|
|
if (pg_attribute_aclcheck(relOid, col, userid,
|
|
remainingPerms) != ACLCHECK_OK)
|
|
return false;
|
|
}
|
|
}
|
|
bms_free(tmpset);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Check that the query does not imply any writes to non-temp tables.
|
|
*
|
|
* Note: in a Hot Standby slave this would need to reject writes to temp
|
|
* tables as well; but an HS slave can't have created any temp tables
|
|
* in the first place, so no need to check that.
|
|
*/
|
|
static void
|
|
ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
|
|
{
|
|
ListCell *l;
|
|
|
|
/*
|
|
* CREATE TABLE AS or SELECT INTO?
|
|
*
|
|
* XXX should we allow this if the destination is temp? Considering that
|
|
* it would still require catalog changes, probably not.
|
|
*/
|
|
if (plannedstmt->intoClause != NULL)
|
|
PreventCommandIfReadOnly(CreateCommandTag((Node *) plannedstmt));
|
|
|
|
/* Fail if write permissions are requested on any non-temp table */
|
|
foreach(l, plannedstmt->rtable)
|
|
{
|
|
RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
|
|
|
|
if (rte->rtekind != RTE_RELATION)
|
|
continue;
|
|
|
|
if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
|
|
continue;
|
|
|
|
if (isTempNamespace(get_rel_namespace(rte->relid)))
|
|
continue;
|
|
|
|
PreventCommandIfReadOnly(CreateCommandTag((Node *) plannedstmt));
|
|
}
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* InitPlan
|
|
*
|
|
* Initializes the query plan: open files, allocate storage
|
|
* and start up the rule manager
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
InitPlan(QueryDesc *queryDesc, int eflags)
|
|
{
|
|
CmdType operation = queryDesc->operation;
|
|
PlannedStmt *plannedstmt = queryDesc->plannedstmt;
|
|
Plan *plan = plannedstmt->planTree;
|
|
List *rangeTable = plannedstmt->rtable;
|
|
EState *estate = queryDesc->estate;
|
|
PlanState *planstate;
|
|
TupleDesc tupType;
|
|
ListCell *l;
|
|
int i;
|
|
|
|
/*
|
|
* Do permissions checks
|
|
*/
|
|
ExecCheckRTPerms(rangeTable, true);
|
|
|
|
/*
|
|
* initialize the node's execution state
|
|
*/
|
|
estate->es_range_table = rangeTable;
|
|
estate->es_plannedstmt = plannedstmt;
|
|
|
|
/*
|
|
* initialize result relation stuff, and open/lock the result rels.
|
|
*
|
|
* We must do this before initializing the plan tree, else we might try to
|
|
* do a lock upgrade if a result rel is also a source rel.
|
|
*/
|
|
if (plannedstmt->resultRelations)
|
|
{
|
|
List *resultRelations = plannedstmt->resultRelations;
|
|
int numResultRelations = list_length(resultRelations);
|
|
ResultRelInfo *resultRelInfos;
|
|
ResultRelInfo *resultRelInfo;
|
|
|
|
resultRelInfos = (ResultRelInfo *)
|
|
palloc(numResultRelations * sizeof(ResultRelInfo));
|
|
resultRelInfo = resultRelInfos;
|
|
foreach(l, resultRelations)
|
|
{
|
|
Index resultRelationIndex = lfirst_int(l);
|
|
Oid resultRelationOid;
|
|
Relation resultRelation;
|
|
|
|
resultRelationOid = getrelid(resultRelationIndex, rangeTable);
|
|
resultRelation = heap_open(resultRelationOid, RowExclusiveLock);
|
|
InitResultRelInfo(resultRelInfo,
|
|
resultRelation,
|
|
resultRelationIndex,
|
|
operation,
|
|
estate->es_instrument);
|
|
resultRelInfo++;
|
|
}
|
|
estate->es_result_relations = resultRelInfos;
|
|
estate->es_num_result_relations = numResultRelations;
|
|
/* es_result_relation_info is NULL except when within ModifyTable */
|
|
estate->es_result_relation_info = NULL;
|
|
}
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Similarly, we have to lock relations selected FOR UPDATE/FOR SHARE
|
|
* before we initialize the plan tree, else we'd be risking lock upgrades.
|
|
* While we are at it, build the ExecRowMark list.
|
|
*/
|
|
estate->es_rowMarks = NIL;
|
|
foreach(l, plannedstmt->rowMarks)
|
|
{
|
|
PlanRowMark *rc = (PlanRowMark *) lfirst(l);
|
|
Oid relid;
|
|
Relation relation;
|
|
ExecRowMark *erm;
|
|
|
|
/* ignore "parent" rowmarks; they are irrelevant at runtime */
|
|
if (rc->isParent)
|
|
continue;
|
|
|
|
switch (rc->markType)
|
|
{
|
|
case ROW_MARK_EXCLUSIVE:
|
|
case ROW_MARK_SHARE:
|
|
relid = getrelid(rc->rti, rangeTable);
|
|
relation = heap_open(relid, RowShareLock);
|
|
break;
|
|
case ROW_MARK_REFERENCE:
|
|
relid = getrelid(rc->rti, rangeTable);
|
|
relation = heap_open(relid, AccessShareLock);
|
|
break;
|
|
case ROW_MARK_COPY:
|
|
/* there's no real table here ... */
|
|
relation = NULL;
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized markType: %d", rc->markType);
|
|
relation = NULL; /* keep compiler quiet */
|
|
break;
|
|
}
|
|
|
|
erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
|
|
erm->relation = relation;
|
|
erm->rti = rc->rti;
|
|
erm->prti = rc->prti;
|
|
erm->markType = rc->markType;
|
|
erm->noWait = rc->noWait;
|
|
erm->ctidAttNo = rc->ctidAttNo;
|
|
erm->toidAttNo = rc->toidAttNo;
|
|
erm->wholeAttNo = rc->wholeAttNo;
|
|
ItemPointerSetInvalid(&(erm->curCtid));
|
|
estate->es_rowMarks = lappend(estate->es_rowMarks, erm);
|
|
}
|
|
|
|
/*
|
|
* 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 && plannedstmt->intoClause != NULL)
|
|
{
|
|
estate->es_select_into = true;
|
|
estate->es_into_oids = interpretOidsOption(plannedstmt->intoClause->options);
|
|
}
|
|
|
|
/*
|
|
* Initialize the executor's tuple table to empty.
|
|
*/
|
|
estate->es_tupleTable = NIL;
|
|
estate->es_trig_tuple_slot = NULL;
|
|
estate->es_trig_oldtup_slot = NULL;
|
|
|
|
/* mark EvalPlanQual not active */
|
|
estate->es_epqTuple = NULL;
|
|
estate->es_epqTupleSet = NULL;
|
|
estate->es_epqScanDone = NULL;
|
|
|
|
/*
|
|
* Initialize private state information for each SubPlan. We must do this
|
|
* before running ExecInitNode on the main query tree, since
|
|
* ExecInitSubPlan expects to be able to find these entries.
|
|
*/
|
|
Assert(estate->es_subplanstates == NIL);
|
|
i = 1; /* subplan indices count from 1 */
|
|
foreach(l, plannedstmt->subplans)
|
|
{
|
|
Plan *subplan = (Plan *) lfirst(l);
|
|
PlanState *subplanstate;
|
|
int sp_eflags;
|
|
|
|
/*
|
|
* A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
|
|
* it is a parameterless subplan (not initplan), we suggest that it be
|
|
* prepared to handle REWIND efficiently; otherwise there is no need.
|
|
*/
|
|
sp_eflags = eflags & EXEC_FLAG_EXPLAIN_ONLY;
|
|
if (bms_is_member(i, plannedstmt->rewindPlanIDs))
|
|
sp_eflags |= EXEC_FLAG_REWIND;
|
|
|
|
subplanstate = ExecInitNode(subplan, estate, sp_eflags);
|
|
|
|
estate->es_subplanstates = lappend(estate->es_subplanstates,
|
|
subplanstate);
|
|
|
|
i++;
|
|
}
|
|
|
|
/*
|
|
* Initialize the private state information for all the nodes in the query
|
|
* tree. This opens files, allocates storage and leaves us ready to start
|
|
* processing tuples.
|
|
*/
|
|
planstate = ExecInitNode(plan, estate, eflags);
|
|
|
|
/*
|
|
* Get the tuple descriptor describing the type of tuples to return. (this
|
|
* is especially important if we are creating a relation with "SELECT
|
|
* INTO")
|
|
*/
|
|
tupType = ExecGetResultType(planstate);
|
|
|
|
/*
|
|
* Initialize the junk filter if needed. SELECT queries need a filter if
|
|
* there are any junk attrs in the top-level tlist.
|
|
*/
|
|
if (operation == CMD_SELECT)
|
|
{
|
|
bool junk_filter_needed = false;
|
|
ListCell *tlist;
|
|
|
|
foreach(tlist, plan->targetlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tlist);
|
|
|
|
if (tle->resjunk)
|
|
{
|
|
junk_filter_needed = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (junk_filter_needed)
|
|
{
|
|
JunkFilter *j;
|
|
|
|
j = ExecInitJunkFilter(planstate->plan->targetlist,
|
|
tupType->tdhasoid,
|
|
ExecInitExtraTupleSlot(estate));
|
|
estate->es_junkFilter = j;
|
|
|
|
/* Want to return the cleaned tuple type */
|
|
tupType = j->jf_cleanTupType;
|
|
}
|
|
}
|
|
|
|
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
|
|
*/
|
|
void
|
|
InitResultRelInfo(ResultRelInfo *resultRelInfo,
|
|
Relation resultRelationDesc,
|
|
Index resultRelationIndex,
|
|
CmdType operation,
|
|
int instrument_options)
|
|
{
|
|
/*
|
|
* Check valid relkind ... parser and/or planner should have noticed this
|
|
* already, but let's make sure.
|
|
*/
|
|
switch (resultRelationDesc->rd_rel->relkind)
|
|
{
|
|
case RELKIND_RELATION:
|
|
/* OK */
|
|
break;
|
|
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;
|
|
default:
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
|
|
errmsg("cannot change relation \"%s\"",
|
|
RelationGetRelationName(resultRelationDesc))));
|
|
break;
|
|
}
|
|
|
|
/* OK, fill in the node */
|
|
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));
|
|
resultRelInfo->ri_TrigWhenExprs = (List **)
|
|
palloc0(n * sizeof(List *));
|
|
if (instrument_options)
|
|
resultRelInfo->ri_TrigInstrument = InstrAlloc(n, instrument_options);
|
|
}
|
|
else
|
|
{
|
|
resultRelInfo->ri_TrigFunctions = NULL;
|
|
resultRelInfo->ri_TrigWhenExprs = 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);
|
|
}
|
|
|
|
/*
|
|
* ExecGetTriggerResultRel
|
|
*
|
|
* Get a ResultRelInfo for a trigger target relation. Most of the time,
|
|
* triggers are fired on one of the result relations of the query, and so
|
|
* we can just return a member of the es_result_relations array. (Note: in
|
|
* self-join situations there might be multiple members with the same OID;
|
|
* if so it doesn't matter which one we pick.) However, it is sometimes
|
|
* necessary to fire triggers on other relations; this happens mainly when an
|
|
* RI update trigger queues additional triggers on other relations, which will
|
|
* be processed in the context of the outer query. For efficiency's sake,
|
|
* we want to have a ResultRelInfo for those triggers too; that can avoid
|
|
* repeated re-opening of the relation. (It also provides a way for EXPLAIN
|
|
* ANALYZE to report the runtimes of such triggers.) So we make additional
|
|
* ResultRelInfo's as needed, and save them in es_trig_target_relations.
|
|
*/
|
|
ResultRelInfo *
|
|
ExecGetTriggerResultRel(EState *estate, Oid relid)
|
|
{
|
|
ResultRelInfo *rInfo;
|
|
int nr;
|
|
ListCell *l;
|
|
Relation rel;
|
|
MemoryContext oldcontext;
|
|
|
|
/* First, search through the query result relations */
|
|
rInfo = estate->es_result_relations;
|
|
nr = estate->es_num_result_relations;
|
|
while (nr > 0)
|
|
{
|
|
if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
|
|
return rInfo;
|
|
rInfo++;
|
|
nr--;
|
|
}
|
|
/* Nope, but maybe we already made an extra ResultRelInfo for it */
|
|
foreach(l, estate->es_trig_target_relations)
|
|
{
|
|
rInfo = (ResultRelInfo *) lfirst(l);
|
|
if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
|
|
return rInfo;
|
|
}
|
|
/* Nope, so we need a new one */
|
|
|
|
/*
|
|
* Open the target relation's relcache entry. We assume that an
|
|
* appropriate lock is still held by the backend from whenever the trigger
|
|
* event got queued, so we need take no new lock here.
|
|
*/
|
|
rel = heap_open(relid, NoLock);
|
|
|
|
/*
|
|
* Make the new entry in the right context. Currently, we don't need any
|
|
* index information in ResultRelInfos used only for triggers, so tell
|
|
* InitResultRelInfo it's a DELETE.
|
|
*/
|
|
oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
|
|
rInfo = makeNode(ResultRelInfo);
|
|
InitResultRelInfo(rInfo,
|
|
rel,
|
|
0, /* dummy rangetable index */
|
|
CMD_DELETE,
|
|
estate->es_instrument);
|
|
estate->es_trig_target_relations =
|
|
lappend(estate->es_trig_target_relations, rInfo);
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return rInfo;
|
|
}
|
|
|
|
/*
|
|
* 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 if we are generating tuples for INSERT or UPDATE,
|
|
* 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 subplans of
|
|
* the ModifyTable node, so ModifyTable has to set es_result_relation_info
|
|
* while initializing each subplan.
|
|
*
|
|
* 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)
|
|
{
|
|
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;
|
|
}
|
|
}
|
|
|
|
if (planstate->state->es_select_into)
|
|
{
|
|
*hasoids = planstate->state->es_into_oids;
|
|
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.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecEndPlan(PlanState *planstate, EState *estate)
|
|
{
|
|
ResultRelInfo *resultRelInfo;
|
|
int i;
|
|
ListCell *l;
|
|
|
|
/*
|
|
* shut down the node-type-specific query processing
|
|
*/
|
|
ExecEndNode(planstate);
|
|
|
|
/*
|
|
* for subplans too
|
|
*/
|
|
foreach(l, estate->es_subplanstates)
|
|
{
|
|
PlanState *subplanstate = (PlanState *) lfirst(l);
|
|
|
|
ExecEndNode(subplanstate);
|
|
}
|
|
|
|
/*
|
|
* destroy the executor's tuple table. Actually we only care about
|
|
* releasing buffer pins and tupdesc refcounts; there's no need to pfree
|
|
* the TupleTableSlots, since the containing memory context is about to go
|
|
* away anyway.
|
|
*/
|
|
ExecResetTupleTable(estate->es_tupleTable, false);
|
|
|
|
/*
|
|
* close 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++;
|
|
}
|
|
|
|
/*
|
|
* likewise close any trigger target relations
|
|
*/
|
|
foreach(l, estate->es_trig_target_relations)
|
|
{
|
|
resultRelInfo = (ResultRelInfo *) lfirst(l);
|
|
/* Close indices and then the relation itself */
|
|
ExecCloseIndices(resultRelInfo);
|
|
heap_close(resultRelInfo->ri_RelationDesc, NoLock);
|
|
}
|
|
|
|
/*
|
|
* close any relations selected FOR UPDATE/FOR SHARE, again keeping locks
|
|
*/
|
|
foreach(l, estate->es_rowMarks)
|
|
{
|
|
ExecRowMark *erm = (ExecRowMark *) lfirst(l);
|
|
|
|
if (erm->relation)
|
|
heap_close(erm->relation, NoLock);
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecutePlan
|
|
*
|
|
* Processes the query plan until we have processed 'numberTuples' tuples,
|
|
* moving in the specified direction.
|
|
*
|
|
* Runs to completion if numberTuples is 0
|
|
*
|
|
* Note: the ctid attribute is a 'junk' attribute that is removed before the
|
|
* user can see it
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
static void
|
|
ExecutePlan(EState *estate,
|
|
PlanState *planstate,
|
|
CmdType operation,
|
|
bool sendTuples,
|
|
long numberTuples,
|
|
ScanDirection direction,
|
|
DestReceiver *dest)
|
|
{
|
|
TupleTableSlot *slot;
|
|
long current_tuple_count;
|
|
|
|
/*
|
|
* initialize local variables
|
|
*/
|
|
current_tuple_count = 0;
|
|
|
|
/*
|
|
* Set the direction.
|
|
*/
|
|
estate->es_direction = direction;
|
|
|
|
/*
|
|
* Loop until we've processed the proper number of tuples from the plan.
|
|
*/
|
|
for (;;)
|
|
{
|
|
/* Reset the per-output-tuple exprcontext */
|
|
ResetPerTupleExprContext(estate);
|
|
|
|
/*
|
|
* Execute the plan and obtain a tuple
|
|
*/
|
|
slot = ExecProcNode(planstate);
|
|
|
|
/*
|
|
* if the tuple is null, then we assume there is nothing more to
|
|
* process so we just end the loop...
|
|
*/
|
|
if (TupIsNull(slot))
|
|
break;
|
|
|
|
/*
|
|
* If we have a junk filter, then project a new tuple with the junk
|
|
* removed.
|
|
*
|
|
* Store this new "clean" tuple in the junkfilter's resultSlot.
|
|
* (Formerly, we stored it back over the "dirty" tuple, which is WRONG
|
|
* because that tuple slot has the wrong descriptor.)
|
|
*/
|
|
if (estate->es_junkFilter != NULL)
|
|
slot = ExecFilterJunk(estate->es_junkFilter, slot);
|
|
|
|
/*
|
|
* If we are supposed to send the tuple somewhere, do so. (In
|
|
* practice, this is probably always the case at this point.)
|
|
*/
|
|
if (sendTuples)
|
|
(*dest->receiveSlot) (slot, dest);
|
|
|
|
/*
|
|
* Count tuples processed, if this is a SELECT. (For other operation
|
|
* types, the ModifyTable plan node must count the appropriate
|
|
* events.)
|
|
*/
|
|
if (operation == CMD_SELECT)
|
|
(estate->es_processed)++;
|
|
|
|
/*
|
|
* check our tuple count.. if we've processed the proper number then
|
|
* quit, else loop again and process more tuples. Zero numberTuples
|
|
* means no limit.
|
|
*/
|
|
current_tuple_count++;
|
|
if (numberTuples && numberTuples == current_tuple_count)
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* 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)));
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* EvalPlanQual logic --- recheck modified tuple(s) to see if we want to
|
|
* process the updated version under READ COMMITTED rules.
|
|
*
|
|
* See backend/executor/README for some info about how this works.
|
|
*/
|
|
|
|
|
|
/*
|
|
* Check a modified tuple to see if we want to process its updated version
|
|
* under READ COMMITTED rules.
|
|
*
|
|
* estate - outer executor state data
|
|
* epqstate - state for EvalPlanQual rechecking
|
|
* relation - table containing tuple
|
|
* 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
|
|
*
|
|
* *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, EPQState *epqstate,
|
|
Relation relation, Index rti,
|
|
ItemPointer tid, TransactionId priorXmax)
|
|
{
|
|
TupleTableSlot *slot;
|
|
HeapTuple copyTuple;
|
|
|
|
Assert(rti > 0);
|
|
|
|
/*
|
|
* Get and lock the updated version of the row; if fail, return NULL.
|
|
*/
|
|
copyTuple = EvalPlanQualFetch(estate, relation, LockTupleExclusive,
|
|
tid, priorXmax);
|
|
|
|
if (copyTuple == NULL)
|
|
return NULL;
|
|
|
|
/*
|
|
* For UPDATE/DELETE we have to return tid of actual row we're executing
|
|
* PQ for.
|
|
*/
|
|
*tid = copyTuple->t_self;
|
|
|
|
/*
|
|
* Need to run a recheck subquery. Initialize or reinitialize EPQ state.
|
|
*/
|
|
EvalPlanQualBegin(epqstate, estate);
|
|
|
|
/*
|
|
* Free old test tuple, if any, and store new tuple where relation's scan
|
|
* node will see it
|
|
*/
|
|
EvalPlanQualSetTuple(epqstate, rti, copyTuple);
|
|
|
|
/*
|
|
* Fetch any non-locked source rows
|
|
*/
|
|
EvalPlanQualFetchRowMarks(epqstate);
|
|
|
|
/*
|
|
* Run the EPQ query. We assume it will return at most one tuple.
|
|
*/
|
|
slot = EvalPlanQualNext(epqstate);
|
|
|
|
/*
|
|
* If we got a tuple, force the slot to materialize the tuple so that it
|
|
* is not dependent on any local state in the EPQ query (in particular,
|
|
* it's highly likely that the slot contains references to any pass-by-ref
|
|
* datums that may be present in copyTuple). As with the next step, this
|
|
* is to guard against early re-use of the EPQ query.
|
|
*/
|
|
if (!TupIsNull(slot))
|
|
(void) ExecMaterializeSlot(slot);
|
|
|
|
/*
|
|
* Clear out the test tuple. This is needed in case the EPQ query is
|
|
* re-used to test a tuple for a different relation. (Not clear that can
|
|
* really happen, but let's be safe.)
|
|
*/
|
|
EvalPlanQualSetTuple(epqstate, rti, NULL);
|
|
|
|
return slot;
|
|
}
|
|
|
|
/*
|
|
* Fetch a copy of the newest version of an outdated tuple
|
|
*
|
|
* estate - executor state data
|
|
* relation - table containing tuple
|
|
* lockmode - requested tuple lock mode
|
|
* *tid - t_ctid from the outdated tuple (ie, next updated version)
|
|
* priorXmax - t_xmax from the outdated tuple
|
|
*
|
|
* Returns a palloc'd copy of the newest tuple version, or NULL if we find
|
|
* that there is no newest version (ie, the row was deleted not updated).
|
|
* If successful, we have locked the newest tuple version, so caller does not
|
|
* need to worry about it changing anymore.
|
|
*
|
|
* Note: properly, lockmode should be declared as enum LockTupleMode,
|
|
* but we use "int" to avoid having to include heapam.h in executor.h.
|
|
*/
|
|
HeapTuple
|
|
EvalPlanQualFetch(EState *estate, Relation relation, int lockmode,
|
|
ItemPointer tid, TransactionId priorXmax)
|
|
{
|
|
HeapTuple copyTuple = NULL;
|
|
HeapTupleData tuple;
|
|
SnapshotData SnapshotDirty;
|
|
|
|
/*
|
|
* fetch target tuple
|
|
*
|
|
* Loop here to deal with updated or busy tuples
|
|
*/
|
|
InitDirtySnapshot(SnapshotDirty);
|
|
tuple.t_self = *tid;
|
|
for (;;)
|
|
{
|
|
Buffer buffer;
|
|
|
|
if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
|
|
{
|
|
HTSU_Result test;
|
|
ItemPointerData update_ctid;
|
|
TransactionId update_xmax;
|
|
|
|
/*
|
|
* 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 es_output_cid: cmin >= current CID 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) >= estate->es_output_cid)
|
|
{
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* This is a live tuple, so now try to lock it.
|
|
*/
|
|
test = heap_lock_tuple(relation, &tuple, &buffer,
|
|
&update_ctid, &update_xmax,
|
|
estate->es_output_cid,
|
|
lockmode, false);
|
|
/* We now have two pins on the buffer, get rid of one */
|
|
ReleaseBuffer(buffer);
|
|
|
|
switch (test)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* treat it as deleted; do not process */
|
|
ReleaseBuffer(buffer);
|
|
return NULL;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
/* successfully locked */
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
ReleaseBuffer(buffer);
|
|
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))
|
|
{
|
|
/* it was updated, so look at the updated version */
|
|
tuple.t_self = update_ctid;
|
|
/* updated row should have xmin matching this xmax */
|
|
priorXmax = update_xmax;
|
|
continue;
|
|
}
|
|
/* tuple was deleted, so give up */
|
|
return NULL;
|
|
|
|
default:
|
|
ReleaseBuffer(buffer);
|
|
elog(ERROR, "unrecognized heap_lock_tuple status: %u",
|
|
test);
|
|
return NULL; /* keep compiler quiet */
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
* process.
|
|
*
|
|
* 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 */
|
|
}
|
|
|
|
/*
|
|
* Return the copied tuple
|
|
*/
|
|
return copyTuple;
|
|
}
|
|
|
|
/*
|
|
* EvalPlanQualInit -- initialize during creation of a plan state node
|
|
* that might need to invoke EPQ processing.
|
|
* Note: subplan can be NULL if it will be set later with EvalPlanQualSetPlan.
|
|
*/
|
|
void
|
|
EvalPlanQualInit(EPQState *epqstate, EState *estate,
|
|
Plan *subplan, int epqParam)
|
|
{
|
|
/* Mark the EPQ state inactive */
|
|
epqstate->estate = NULL;
|
|
epqstate->planstate = NULL;
|
|
epqstate->origslot = NULL;
|
|
/* ... and remember data that EvalPlanQualBegin will need */
|
|
epqstate->plan = subplan;
|
|
epqstate->rowMarks = NIL;
|
|
epqstate->epqParam = epqParam;
|
|
}
|
|
|
|
/*
|
|
* EvalPlanQualSetPlan -- set or change subplan of an EPQState.
|
|
*
|
|
* We need this so that ModifyTuple can deal with multiple subplans.
|
|
*/
|
|
void
|
|
EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan)
|
|
{
|
|
/* If we have a live EPQ query, shut it down */
|
|
EvalPlanQualEnd(epqstate);
|
|
/* And set/change the plan pointer */
|
|
epqstate->plan = subplan;
|
|
}
|
|
|
|
/*
|
|
* EvalPlanQualAddRowMark -- add an ExecRowMark that EPQ needs to handle.
|
|
*
|
|
* Currently, only non-locking RowMarks are supported.
|
|
*/
|
|
void
|
|
EvalPlanQualAddRowMark(EPQState *epqstate, ExecRowMark *erm)
|
|
{
|
|
if (RowMarkRequiresRowShareLock(erm->markType))
|
|
elog(ERROR, "EvalPlanQual doesn't support locking rowmarks");
|
|
epqstate->rowMarks = lappend(epqstate->rowMarks, erm);
|
|
}
|
|
|
|
/*
|
|
* Install one test tuple into EPQ state, or clear test tuple if tuple == NULL
|
|
*
|
|
* NB: passed tuple must be palloc'd; it may get freed later
|
|
*/
|
|
void
|
|
EvalPlanQualSetTuple(EPQState *epqstate, Index rti, HeapTuple tuple)
|
|
{
|
|
EState *estate = epqstate->estate;
|
|
|
|
Assert(rti > 0);
|
|
|
|
/*
|
|
* free old test tuple, if any, and store new tuple where relation's scan
|
|
* node will see it
|
|
*/
|
|
if (estate->es_epqTuple[rti - 1] != NULL)
|
|
heap_freetuple(estate->es_epqTuple[rti - 1]);
|
|
estate->es_epqTuple[rti - 1] = tuple;
|
|
estate->es_epqTupleSet[rti - 1] = true;
|
|
}
|
|
|
|
/*
|
|
* Fetch back the current test tuple (if any) for the specified RTI
|
|
*/
|
|
HeapTuple
|
|
EvalPlanQualGetTuple(EPQState *epqstate, Index rti)
|
|
{
|
|
EState *estate = epqstate->estate;
|
|
|
|
Assert(rti > 0);
|
|
|
|
return estate->es_epqTuple[rti - 1];
|
|
}
|
|
|
|
/*
|
|
* Fetch the current row values for any non-locked relations that need
|
|
* to be scanned by an EvalPlanQual operation. origslot must have been set
|
|
* to contain the current result row (top-level row) that we need to recheck.
|
|
*/
|
|
void
|
|
EvalPlanQualFetchRowMarks(EPQState *epqstate)
|
|
{
|
|
ListCell *l;
|
|
|
|
Assert(epqstate->origslot != NULL);
|
|
|
|
foreach(l, epqstate->rowMarks)
|
|
{
|
|
ExecRowMark *erm = (ExecRowMark *) lfirst(l);
|
|
Datum datum;
|
|
bool isNull;
|
|
HeapTupleData tuple;
|
|
|
|
/* clear any leftover test tuple for this rel */
|
|
EvalPlanQualSetTuple(epqstate, erm->rti, NULL);
|
|
|
|
if (erm->relation)
|
|
{
|
|
Buffer buffer;
|
|
|
|
Assert(erm->markType == ROW_MARK_REFERENCE);
|
|
|
|
/* if child rel, must check whether it produced this row */
|
|
if (erm->rti != erm->prti)
|
|
{
|
|
Oid tableoid;
|
|
|
|
datum = ExecGetJunkAttribute(epqstate->origslot,
|
|
erm->toidAttNo,
|
|
&isNull);
|
|
/* non-locked rels could be on the inside of outer joins */
|
|
if (isNull)
|
|
continue;
|
|
tableoid = DatumGetObjectId(datum);
|
|
|
|
if (tableoid != RelationGetRelid(erm->relation))
|
|
{
|
|
/* this child is inactive right now */
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* fetch the tuple's ctid */
|
|
datum = ExecGetJunkAttribute(epqstate->origslot,
|
|
erm->ctidAttNo,
|
|
&isNull);
|
|
/* non-locked rels could be on the inside of outer joins */
|
|
if (isNull)
|
|
continue;
|
|
tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
|
|
|
|
/* okay, fetch the tuple */
|
|
if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
|
|
false, NULL))
|
|
elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
|
|
|
|
/* successful, copy and store tuple */
|
|
EvalPlanQualSetTuple(epqstate, erm->rti,
|
|
heap_copytuple(&tuple));
|
|
ReleaseBuffer(buffer);
|
|
}
|
|
else
|
|
{
|
|
HeapTupleHeader td;
|
|
|
|
Assert(erm->markType == ROW_MARK_COPY);
|
|
|
|
/* fetch the whole-row Var for the relation */
|
|
datum = ExecGetJunkAttribute(epqstate->origslot,
|
|
erm->wholeAttNo,
|
|
&isNull);
|
|
/* non-locked rels could be on the inside of outer joins */
|
|
if (isNull)
|
|
continue;
|
|
td = DatumGetHeapTupleHeader(datum);
|
|
|
|
/* build a temporary HeapTuple control structure */
|
|
tuple.t_len = HeapTupleHeaderGetDatumLength(td);
|
|
ItemPointerSetInvalid(&(tuple.t_self));
|
|
tuple.t_tableOid = InvalidOid;
|
|
tuple.t_data = td;
|
|
|
|
/* copy and store tuple */
|
|
EvalPlanQualSetTuple(epqstate, erm->rti,
|
|
heap_copytuple(&tuple));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Fetch the next row (if any) from EvalPlanQual testing
|
|
*
|
|
* (In practice, there should never be more than one row...)
|
|
*/
|
|
TupleTableSlot *
|
|
EvalPlanQualNext(EPQState *epqstate)
|
|
{
|
|
MemoryContext oldcontext;
|
|
TupleTableSlot *slot;
|
|
|
|
oldcontext = MemoryContextSwitchTo(epqstate->estate->es_query_cxt);
|
|
slot = ExecProcNode(epqstate->planstate);
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return slot;
|
|
}
|
|
|
|
/*
|
|
* Initialize or reset an EvalPlanQual state tree
|
|
*/
|
|
void
|
|
EvalPlanQualBegin(EPQState *epqstate, EState *parentestate)
|
|
{
|
|
EState *estate = epqstate->estate;
|
|
|
|
if (estate == NULL)
|
|
{
|
|
/* First time through, so create a child EState */
|
|
EvalPlanQualStart(epqstate, parentestate, epqstate->plan);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We already have a suitable child EPQ tree, so just reset it.
|
|
*/
|
|
int rtsize = list_length(parentestate->es_range_table);
|
|
PlanState *planstate = epqstate->planstate;
|
|
|
|
MemSet(estate->es_epqScanDone, 0, rtsize * sizeof(bool));
|
|
|
|
/* Recopy current values of parent parameters */
|
|
if (parentestate->es_plannedstmt->nParamExec > 0)
|
|
{
|
|
int i = parentestate->es_plannedstmt->nParamExec;
|
|
|
|
while (--i >= 0)
|
|
{
|
|
/* copy value if any, but not execPlan link */
|
|
estate->es_param_exec_vals[i].value =
|
|
parentestate->es_param_exec_vals[i].value;
|
|
estate->es_param_exec_vals[i].isnull =
|
|
parentestate->es_param_exec_vals[i].isnull;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Mark child plan tree as needing rescan at all scan nodes. The
|
|
* first ExecProcNode will take care of actually doing the rescan.
|
|
*/
|
|
planstate->chgParam = bms_add_member(planstate->chgParam,
|
|
epqstate->epqParam);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Start execution of an EvalPlanQual plan tree.
|
|
*
|
|
* This is a cut-down version of ExecutorStart(): we copy some state from
|
|
* the top-level estate rather than initializing it fresh.
|
|
*/
|
|
static void
|
|
EvalPlanQualStart(EPQState *epqstate, EState *parentestate, Plan *planTree)
|
|
{
|
|
EState *estate;
|
|
int rtsize;
|
|
MemoryContext oldcontext;
|
|
ListCell *l;
|
|
|
|
rtsize = list_length(parentestate->es_range_table);
|
|
|
|
epqstate->estate = estate = CreateExecutorState();
|
|
|
|
oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
|
|
|
|
/*
|
|
* Child EPQ EStates share the parent'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.
|
|
*/
|
|
estate->es_direction = ForwardScanDirection;
|
|
estate->es_snapshot = parentestate->es_snapshot;
|
|
estate->es_crosscheck_snapshot = parentestate->es_crosscheck_snapshot;
|
|
estate->es_range_table = parentestate->es_range_table;
|
|
estate->es_plannedstmt = parentestate->es_plannedstmt;
|
|
estate->es_junkFilter = parentestate->es_junkFilter;
|
|
estate->es_output_cid = parentestate->es_output_cid;
|
|
estate->es_result_relations = parentestate->es_result_relations;
|
|
estate->es_num_result_relations = parentestate->es_num_result_relations;
|
|
estate->es_result_relation_info = parentestate->es_result_relation_info;
|
|
/* es_trig_target_relations must NOT be copied */
|
|
estate->es_rowMarks = parentestate->es_rowMarks;
|
|
estate->es_instrument = parentestate->es_instrument;
|
|
estate->es_select_into = parentestate->es_select_into;
|
|
estate->es_into_oids = parentestate->es_into_oids;
|
|
|
|
/*
|
|
* The external param list is simply shared from parent. The internal
|
|
* param workspace has to be local state, but we copy the initial values
|
|
* from the parent, so as to have access to any param values that were
|
|
* already set from other parts of the parent's plan tree.
|
|
*/
|
|
estate->es_param_list_info = parentestate->es_param_list_info;
|
|
if (parentestate->es_plannedstmt->nParamExec > 0)
|
|
{
|
|
int i = parentestate->es_plannedstmt->nParamExec;
|
|
|
|
estate->es_param_exec_vals = (ParamExecData *)
|
|
palloc0(i * sizeof(ParamExecData));
|
|
while (--i >= 0)
|
|
{
|
|
/* copy value if any, but not execPlan link */
|
|
estate->es_param_exec_vals[i].value =
|
|
parentestate->es_param_exec_vals[i].value;
|
|
estate->es_param_exec_vals[i].isnull =
|
|
parentestate->es_param_exec_vals[i].isnull;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Each EState must have its own es_epqScanDone state, but if we have
|
|
* nested EPQ checks they should share es_epqTuple arrays. This allows
|
|
* sub-rechecks to inherit the values being examined by an outer recheck.
|
|
*/
|
|
estate->es_epqScanDone = (bool *) palloc0(rtsize * sizeof(bool));
|
|
if (parentestate->es_epqTuple != NULL)
|
|
{
|
|
estate->es_epqTuple = parentestate->es_epqTuple;
|
|
estate->es_epqTupleSet = parentestate->es_epqTupleSet;
|
|
}
|
|
else
|
|
{
|
|
estate->es_epqTuple = (HeapTuple *)
|
|
palloc0(rtsize * sizeof(HeapTuple));
|
|
estate->es_epqTupleSet = (bool *)
|
|
palloc0(rtsize * sizeof(bool));
|
|
}
|
|
|
|
/*
|
|
* Each estate also has its own tuple table.
|
|
*/
|
|
estate->es_tupleTable = NIL;
|
|
|
|
/*
|
|
* Initialize private state information for each SubPlan. We must do this
|
|
* before running ExecInitNode on the main query tree, since
|
|
* ExecInitSubPlan expects to be able to find these entries. Some of the
|
|
* SubPlans might not be used in the part of the plan tree we intend to
|
|
* run, but since it's not easy to tell which, we just initialize them
|
|
* all.
|
|
*/
|
|
Assert(estate->es_subplanstates == NIL);
|
|
foreach(l, parentestate->es_plannedstmt->subplans)
|
|
{
|
|
Plan *subplan = (Plan *) lfirst(l);
|
|
PlanState *subplanstate;
|
|
|
|
subplanstate = ExecInitNode(subplan, estate, 0);
|
|
|
|
estate->es_subplanstates = lappend(estate->es_subplanstates,
|
|
subplanstate);
|
|
}
|
|
|
|
/*
|
|
* Initialize the private state information for all the nodes in the part
|
|
* of the plan tree we need to run. This opens files, allocates storage
|
|
* and leaves us ready to start processing tuples.
|
|
*/
|
|
epqstate->planstate = ExecInitNode(planTree, estate, 0);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
/*
|
|
* EvalPlanQualEnd -- shut down at termination of parent plan state node,
|
|
* or if we are done with the current EPQ child.
|
|
*
|
|
* This is a cut-down version of ExecutorEnd(); basically we want to do most
|
|
* of the normal cleanup, but *not* close result relations (which we are
|
|
* just sharing from the outer query). We do, however, have to close any
|
|
* trigger target relations that got opened, since those are not shared.
|
|
* (There probably shouldn't be any of the latter, but just in case...)
|
|
*/
|
|
void
|
|
EvalPlanQualEnd(EPQState *epqstate)
|
|
{
|
|
EState *estate = epqstate->estate;
|
|
MemoryContext oldcontext;
|
|
ListCell *l;
|
|
|
|
if (estate == NULL)
|
|
return; /* idle, so nothing to do */
|
|
|
|
oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
|
|
|
|
ExecEndNode(epqstate->planstate);
|
|
|
|
foreach(l, estate->es_subplanstates)
|
|
{
|
|
PlanState *subplanstate = (PlanState *) lfirst(l);
|
|
|
|
ExecEndNode(subplanstate);
|
|
}
|
|
|
|
/* throw away the per-estate tuple table */
|
|
ExecResetTupleTable(estate->es_tupleTable, false);
|
|
|
|
/* close any trigger target relations attached to this EState */
|
|
foreach(l, estate->es_trig_target_relations)
|
|
{
|
|
ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
|
|
|
|
/* Close indices and then the relation itself */
|
|
ExecCloseIndices(resultRelInfo);
|
|
heap_close(resultRelInfo->ri_RelationDesc, NoLock);
|
|
}
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
FreeExecutorState(estate);
|
|
|
|
/* Mark EPQState idle */
|
|
epqstate->estate = NULL;
|
|
epqstate->planstate = NULL;
|
|
epqstate->origslot = 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.
|
|
*/
|
|
|
|
typedef struct
|
|
{
|
|
DestReceiver pub; /* publicly-known function pointers */
|
|
EState *estate; /* EState we are working with */
|
|
Relation rel; /* Relation to write to */
|
|
int hi_options; /* heap_insert performance options */
|
|
BulkInsertState bistate; /* bulk insert state */
|
|
} 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)
|
|
{
|
|
IntoClause *into = queryDesc->plannedstmt->intoClause;
|
|
EState *estate = queryDesc->estate;
|
|
Relation intoRelationDesc;
|
|
char *intoName;
|
|
Oid namespaceId;
|
|
Oid tablespaceId;
|
|
Datum reloptions;
|
|
AclResult aclresult;
|
|
Oid intoRelationId;
|
|
TupleDesc tupdesc;
|
|
DR_intorel *myState;
|
|
static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
|
|
|
|
Assert(into);
|
|
|
|
/*
|
|
* XXX This code needs to be kept in sync with DefineRelation(). Maybe we
|
|
* should try to use that function instead.
|
|
*/
|
|
|
|
/*
|
|
* Check consistency of arguments
|
|
*/
|
|
if (into->onCommit != ONCOMMIT_NOOP && !into->rel->istemp)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
|
|
errmsg("ON COMMIT can only be used on temporary tables")));
|
|
|
|
/*
|
|
* Security check: disallow creating temp tables from security-restricted
|
|
* code. This is needed because calling code might not expect untrusted
|
|
* tables to appear in pg_temp at the front of its search path.
|
|
*/
|
|
if (into->rel->istemp && InSecurityRestrictedOperation())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
errmsg("cannot create temporary table within security-restricted operation")));
|
|
|
|
/*
|
|
* Find namespace to create in, check its permissions
|
|
*/
|
|
intoName = into->rel->relname;
|
|
namespaceId = RangeVarGetCreationNamespace(into->rel);
|
|
|
|
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 (into->tableSpaceName)
|
|
{
|
|
tablespaceId = get_tablespace_oid(into->tableSpaceName);
|
|
if (!OidIsValid(tablespaceId))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("tablespace \"%s\" does not exist",
|
|
into->tableSpaceName)));
|
|
}
|
|
else
|
|
{
|
|
tablespaceId = GetDefaultTablespace(into->rel->istemp);
|
|
/* note InvalidOid is OK in this case */
|
|
}
|
|
|
|
/* Check permissions except when using the database's default space */
|
|
if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
|
|
{
|
|
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,
|
|
into->options,
|
|
NULL,
|
|
validnsps,
|
|
true,
|
|
false);
|
|
(void) heap_reloptions(RELKIND_RELATION, reloptions, true);
|
|
|
|
/* Copy the tupdesc because heap_create_with_catalog modifies it */
|
|
tupdesc = CreateTupleDescCopy(queryDesc->tupDesc);
|
|
|
|
/* Now we can actually create the new relation */
|
|
intoRelationId = heap_create_with_catalog(intoName,
|
|
namespaceId,
|
|
tablespaceId,
|
|
InvalidOid,
|
|
InvalidOid,
|
|
InvalidOid,
|
|
GetUserId(),
|
|
tupdesc,
|
|
NIL,
|
|
RELKIND_RELATION,
|
|
false,
|
|
false,
|
|
true,
|
|
0,
|
|
into->onCommit,
|
|
reloptions,
|
|
true,
|
|
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.
|
|
*/
|
|
reloptions = transformRelOptions((Datum) 0,
|
|
into->options,
|
|
"toast",
|
|
validnsps,
|
|
true,
|
|
false);
|
|
|
|
(void) heap_reloptions(RELKIND_TOASTVALUE, reloptions, true);
|
|
|
|
AlterTableCreateToastTable(intoRelationId, reloptions);
|
|
|
|
/*
|
|
* And open the constructed table for writing.
|
|
*/
|
|
intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
|
|
|
|
/*
|
|
* Now replace the query's DestReceiver with one for SELECT INTO
|
|
*/
|
|
queryDesc->dest = CreateDestReceiver(DestIntoRel);
|
|
myState = (DR_intorel *) queryDesc->dest;
|
|
Assert(myState->pub.mydest == DestIntoRel);
|
|
myState->estate = estate;
|
|
myState->rel = intoRelationDesc;
|
|
|
|
/*
|
|
* We can skip WAL-logging the insertions, unless PITR or streaming
|
|
* replication is in use. We can skip the FSM in any case.
|
|
*/
|
|
myState->hi_options = HEAP_INSERT_SKIP_FSM |
|
|
(XLogIsNeeded() ? 0 : HEAP_INSERT_SKIP_WAL);
|
|
myState->bistate = GetBulkInsertState();
|
|
|
|
/* Not using WAL requires smgr_targblock be initially invalid */
|
|
Assert(RelationGetTargetBlock(intoRelationDesc) == InvalidBlockNumber);
|
|
}
|
|
|
|
/*
|
|
* CloseIntoRel --- clean up SELECT INTO at ExecutorEnd time
|
|
*/
|
|
static void
|
|
CloseIntoRel(QueryDesc *queryDesc)
|
|
{
|
|
DR_intorel *myState = (DR_intorel *) queryDesc->dest;
|
|
|
|
/* OpenIntoRel might never have gotten called */
|
|
if (myState && myState->pub.mydest == DestIntoRel && myState->rel)
|
|
{
|
|
FreeBulkInsertState(myState->bistate);
|
|
|
|
/* If we skipped using WAL, must heap_sync before commit */
|
|
if (myState->hi_options & HEAP_INSERT_SKIP_WAL)
|
|
heap_sync(myState->rel);
|
|
|
|
/* close rel, but keep lock until commit */
|
|
heap_close(myState->rel, NoLock);
|
|
|
|
myState->rel = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* CreateIntoRelDestReceiver -- create a suitable DestReceiver object
|
|
*/
|
|
DestReceiver *
|
|
CreateIntoRelDestReceiver(void)
|
|
{
|
|
DR_intorel *self = (DR_intorel *) palloc0(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;
|
|
|
|
/* private fields will be set by OpenIntoRel */
|
|
|
|
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;
|
|
HeapTuple tuple;
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot, making sure we have a
|
|
* writable copy
|
|
*/
|
|
tuple = ExecMaterializeSlot(slot);
|
|
|
|
/*
|
|
* force assignment of new OID (see comments in ExecInsert)
|
|
*/
|
|
if (myState->rel->rd_rel->relhasoids)
|
|
HeapTupleSetOid(tuple, InvalidOid);
|
|
|
|
heap_insert(myState->rel,
|
|
tuple,
|
|
myState->estate->es_output_cid,
|
|
myState->hi_options,
|
|
myState->bistate);
|
|
|
|
/* We know this is a newly created relation, so there are no indexes */
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|