* INTERFACE ROUTINES
* ExecutorStart()
* ExecutorRun()
+ * ExecutorFinish()
* ExecutorEnd()
*
- * The old ExecutorMain() has been replaced by ExecutorStart(),
- * ExecutorRun() and ExecutorEnd()
+ * These four procedures are the external interface to the executor.
+ * In each case, the query descriptor is required as an argument.
*
- * These three procedures are the external interfaces to the executor.
- * In each case, the query descriptor and the execution state is required
- * as arguments
- *
- * ExecutorStart() must be called at the beginning of any execution of any
- * query plan and ExecutorEnd() should always be called at the end of
- * execution of a plan.
+ * ExecutorStart must be called at the beginning of execution of any
+ * query plan and ExecutorEnd must always be called at the end of
+ * execution of a plan (unless it is aborted due to error).
*
* ExecutorRun accepts direction and count arguments that specify whether
* the plan is to be executed forwards, backwards, and for how many tuples.
+ * In some cases ExecutorRun may be called multiple times to process all
+ * the tuples for a plan. It is also acceptable to stop short of executing
+ * the whole plan (but only if it is a SELECT).
+ *
+ * ExecutorFinish must be called after the final ExecutorRun call and
+ * before ExecutorEnd. This can be omitted only in case of EXPLAIN,
+ * which should also omit ExecutorRun.
*
- * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.168 2002/06/26 21:58:56 momjian Exp $
+ * src/backend/executor/execMain.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
-#include "access/heapam.h"
-#include "catalog/heap.h"
+#include "access/htup_details.h"
+#include "access/sysattr.h"
+#include "access/transam.h"
+#include "access/xact.h"
#include "catalog/namespace.h"
-#include "commands/tablecmds.h"
+#include "commands/matview.h"
#include "commands/trigger.h"
#include "executor/execdebug.h"
-#include "executor/execdefs.h"
+#include "foreign/fdwapi.h"
+#include "mb/pg_wchar.h"
#include "miscadmin.h"
-#include "optimizer/var.h"
+#include "optimizer/clauses.h"
#include "parser/parsetree.h"
+#include "storage/bufmgr.h"
+#include "storage/lmgr.h"
+#include "tcop/utility.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/rls.h"
+#include "utils/snapmgr.h"
+#include "utils/tqual.h"
+
+
+/* Hooks for plugins to get control in ExecutorStart/Run/Finish/End */
+ExecutorStart_hook_type ExecutorStart_hook = NULL;
+ExecutorRun_hook_type ExecutorRun_hook = NULL;
+ExecutorFinish_hook_type ExecutorFinish_hook = NULL;
+ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
+/* Hook for plugin to get control in ExecCheckRTPerms() */
+ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
/* decls for local routines only used within this module */
-static TupleDesc InitPlan(CmdType operation,
- Query *parseTree,
- Plan *plan,
- EState *estate);
-static void initResultRelInfo(ResultRelInfo *resultRelInfo,
- Index resultRelationIndex,
- List *rangeTable,
- CmdType operation);
-static void EndPlan(Plan *plan, EState *estate);
-static TupleTableSlot *ExecutePlan(EState *estate, Plan *plan,
+static void InitPlan(QueryDesc *queryDesc, int eflags);
+static void CheckValidRowMarkRel(Relation rel, RowMarkType markType);
+static void ExecPostprocessPlan(EState *estate);
+static void ExecEndPlan(PlanState *planstate, EState *estate);
+static void ExecutePlan(EState *estate, PlanState *planstate,
CmdType operation,
+ bool sendTuples,
long numberTuples,
ScanDirection direction,
- DestReceiver *destfunc);
-static void ExecSelect(TupleTableSlot *slot,
- DestReceiver *destfunc,
- EState *estate);
-static void ExecInsert(TupleTableSlot *slot, ItemPointer tupleid,
- EState *estate);
-static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
- EState *estate);
-static void ExecUpdate(TupleTableSlot *slot, ItemPointer tupleid,
- EState *estate);
-static TupleTableSlot *EvalPlanQualNext(EState *estate);
-static void EndEvalPlanQual(EState *estate);
-static void ExecCheckQueryPerms(CmdType operation, Query *parseTree,
- Plan *plan);
-static void ExecCheckPlanPerms(Plan *plan, List *rangeTable,
- CmdType operation);
-static void ExecCheckRTPerms(List *rangeTable, CmdType operation);
-static void ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation);
+ DestReceiver *dest);
+static bool ExecCheckRTEPerms(RangeTblEntry *rte);
+static bool ExecCheckRTEPermsModified(Oid relOid, Oid userid,
+ Bitmapset *modifiedCols,
+ AclMode requiredPerms);
+static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
+static char *ExecBuildSlotValueDescription(Oid reloid,
+ TupleTableSlot *slot,
+ TupleDesc tupdesc,
+ Bitmapset *modifiedCols,
+ int maxfieldlen);
+static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
+ Plan *planTree);
+
+/*
+ * Note that GetUpdatedColumns() also exists in commands/trigger.c. There does
+ * not appear to be any good header to put it into, given the structures that
+ * it uses, so we let them be duplicated. Be sure to update both if one needs
+ * to be changed, however.
+ */
+#define GetInsertedColumns(relinfo, estate) \
+ (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->insertedCols)
+#define GetUpdatedColumns(relinfo, estate) \
+ (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->updatedCols)
/* end of local decls */
* This routine must be called at the beginning of any execution of any
* query plan
*
- * returns a TupleDesc which describes the attributes of the tuples to
- * be returned by the query. (Same value is saved in queryDesc)
+ * Takes a QueryDesc previously created by CreateQueryDesc (which is separate
+ * only because some places use QueryDescs for utility commands). The tupDesc
+ * field of the QueryDesc is filled in to describe the tuples that will be
+ * returned, and the internal fields (estate and planstate) are set up.
+ *
+ * eflags contains flag bits as described in executor.h.
+ *
+ * NB: the CurrentMemoryContext when this is called will become the parent
+ * of the per-query context used for this Executor invocation.
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ExecutorStart is called. Such a plugin would
+ * normally call standard_ExecutorStart().
*
- * NB: the CurrentMemoryContext when this is called must be the context
- * to be used as the per-query context for the query plan. ExecutorRun()
- * and ExecutorEnd() must be called in this same memory context.
* ----------------------------------------------------------------
*/
-TupleDesc
-ExecutorStart(QueryDesc *queryDesc, EState *estate)
+void
+ExecutorStart(QueryDesc *queryDesc, int eflags)
{
- TupleDesc result;
+ if (ExecutorStart_hook)
+ (*ExecutorStart_hook) (queryDesc, eflags);
+ else
+ standard_ExecutorStart(queryDesc, eflags);
+}
- /* sanity checks */
+void
+standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
+{
+ EState *estate;
+ MemoryContext oldcontext;
+
+ /* sanity checks: queryDesc must not be started already */
Assert(queryDesc != NULL);
+ Assert(queryDesc->estate == NULL);
- if (queryDesc->plantree->nParamExec > 0)
- {
+ /*
+ * If the transaction is read-only, we need to check if any writes are
+ * planned to non-temporary tables. EXPLAIN is considered read-only.
+ *
+ * Don't allow writes in parallel mode. Supporting UPDATE and DELETE
+ * would require (a) storing the combocid hash in shared memory, rather
+ * than synchronizing it just once at the start of parallelism, and (b) an
+ * alternative to heap_update()'s reliance on xmax for mutual exclusion.
+ * INSERT may have no such troubles, but we forbid it to simplify the
+ * checks.
+ *
+ * We have lower-level defenses in CommandCounterIncrement and elsewhere
+ * against performing unsafe operations in parallel mode, but this gives a
+ * more user-friendly error message.
+ */
+ if ((XactReadOnly || IsInParallelMode()) &&
+ !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ ExecCheckXactReadOnly(queryDesc->plannedstmt);
+
+ /*
+ * Build EState, switch into per-query memory context for startup.
+ */
+ estate = CreateExecutorState();
+ queryDesc->estate = estate;
+
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ /*
+ * Fill in external parameters, if any, from queryDesc; and allocate
+ * workspace for internal parameters
+ */
+ estate->es_param_list_info = queryDesc->params;
+
+ if (queryDesc->plannedstmt->nParamExec > 0)
estate->es_param_exec_vals = (ParamExecData *)
- palloc(queryDesc->plantree->nParamExec * sizeof(ParamExecData));
- MemSet(estate->es_param_exec_vals, 0,
- queryDesc->plantree->nParamExec * sizeof(ParamExecData));
+ palloc0(queryDesc->plannedstmt->nParamExec * sizeof(ParamExecData));
+
+ /*
+ * If non-read-only query, set the command ID to mark output tuples with
+ */
+ switch (queryDesc->operation)
+ {
+ case CMD_SELECT:
+
+ /*
+ * SELECT FOR [KEY] UPDATE/SHARE and modifying CTEs need to mark
+ * tuples
+ */
+ if (queryDesc->plannedstmt->rowMarks != NIL ||
+ queryDesc->plannedstmt->hasModifyingCTE)
+ estate->es_output_cid = GetCurrentCommandId(true);
+
+ /*
+ * A SELECT without modifying CTEs can't possibly queue triggers,
+ * so force skip-triggers mode. This is just a marginal efficiency
+ * hack, since AfterTriggerBeginQuery/AfterTriggerEndQuery aren't
+ * all that expensive, but we might as well do it.
+ */
+ if (!queryDesc->plannedstmt->hasModifyingCTE)
+ eflags |= EXEC_FLAG_SKIP_TRIGGERS;
+ break;
+
+ case CMD_INSERT:
+ case CMD_DELETE:
+ case CMD_UPDATE:
+ estate->es_output_cid = GetCurrentCommandId(true);
+ break;
+
+ default:
+ elog(ERROR, "unrecognized operation code: %d",
+ (int) queryDesc->operation);
+ break;
}
/*
- * Make our own private copy of the current query snapshot data.
- *
- * This "freezes" our idea of which tuples are good and which are not
- * for the life of this query, even if it outlives the current command
- * and current snapshot.
+ * Copy other important information into the EState
*/
- estate->es_snapshot = CopyQuerySnapshot();
+ estate->es_snapshot = RegisterSnapshot(queryDesc->snapshot);
+ estate->es_crosscheck_snapshot = RegisterSnapshot(queryDesc->crosscheck_snapshot);
+ estate->es_top_eflags = eflags;
+ estate->es_instrument = queryDesc->instrument_options;
/*
- * Initialize the plan
+ * Initialize the plan state tree
*/
- result = InitPlan(queryDesc->operation,
- queryDesc->parsetree,
- queryDesc->plantree,
- estate);
+ InitPlan(queryDesc, eflags);
- queryDesc->tupDesc = result;
+ /*
+ * Set up an AFTER-trigger statement context, unless told not to, or
+ * unless it's EXPLAIN-only mode (when ExecutorFinish won't be called).
+ */
+ if (!(eflags & (EXEC_FLAG_SKIP_TRIGGERS | EXEC_FLAG_EXPLAIN_ONLY)))
+ AfterTriggerBeginQuery();
- return result;
+ /* Enter parallel mode, if required by the query. */
+ if (queryDesc->plannedstmt->parallelModeNeeded &&
+ !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ EnterParallelMode();
+
+ MemoryContextSwitchTo(oldcontext);
}
/* ----------------------------------------------------------------
* except to start up/shut down the destination. Otherwise,
* we retrieve up to 'count' tuples in the specified direction.
*
- * Note: count = 0 is interpreted as no portal limit, e.g. run to
- * completion.
+ * Note: count = 0 is interpreted as no portal limit, i.e., run to
+ * completion. Also note that the count limit is only applied to
+ * retrieved tuples, not for instance to those inserted/updated/deleted
+ * by a ModifyTable plan node.
+ *
+ * There is no return value, but output tuples (if any) are sent to
+ * the destination receiver specified in the QueryDesc; and the number
+ * of tuples processed at the top level can be found in
+ * estate->es_processed.
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ExecutorRun is called. Such a plugin would
+ * normally call standard_ExecutorRun().
*
* ----------------------------------------------------------------
*/
-TupleTableSlot *
-ExecutorRun(QueryDesc *queryDesc, EState *estate,
+void
+ExecutorRun(QueryDesc *queryDesc,
ScanDirection direction, long count)
{
+ if (ExecutorRun_hook)
+ (*ExecutorRun_hook) (queryDesc, direction, count);
+ else
+ standard_ExecutorRun(queryDesc, direction, count);
+}
+
+void
+standard_ExecutorRun(QueryDesc *queryDesc,
+ ScanDirection direction, long count)
+{
+ EState *estate;
CmdType operation;
- Plan *plan;
- CommandDest dest;
- DestReceiver *destfunc;
- TupleTableSlot *result;
+ DestReceiver *dest;
+ bool sendTuples;
+ MemoryContext oldcontext;
+
+ /* sanity checks */
+ Assert(queryDesc != NULL);
+
+ estate = queryDesc->estate;
+
+ Assert(estate != NULL);
+ Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
/*
- * sanity checks
+ * Switch into per-query memory context
*/
- Assert(queryDesc != NULL);
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ /* Allow instrumentation of Executor overall runtime */
+ if (queryDesc->totaltime)
+ InstrStartNode(queryDesc->totaltime);
/*
- * extract information from the query descriptor and the query
- * feature.
+ * extract information from the query descriptor and the query feature.
*/
operation = queryDesc->operation;
- plan = queryDesc->plantree;
dest = queryDesc->dest;
/*
- * startup tuple receiver
+ * startup tuple receiver, if we will be emitting tuples
*/
estate->es_processed = 0;
estate->es_lastoid = InvalidOid;
- destfunc = DestToFunction(dest);
- (*destfunc->setup) (destfunc, (int) operation,
- queryDesc->portalName, queryDesc->tupDesc);
+ sendTuples = (operation == CMD_SELECT ||
+ queryDesc->plannedstmt->hasReturning);
+
+ if (sendTuples)
+ (*dest->rStartup) (dest, operation, queryDesc->tupDesc);
/*
* run plan
*/
- if (direction == NoMovementScanDirection)
- result = NULL;
- else
- result = ExecutePlan(estate,
- plan,
- operation,
- count,
- direction,
- destfunc);
+ if (!ScanDirectionIsNoMovement(direction))
+ ExecutePlan(estate,
+ queryDesc->planstate,
+ operation,
+ sendTuples,
+ count,
+ direction,
+ dest);
+
+ /* Allow nodes to release or shut down resources. */
+ (void) ExecShutdownNode(queryDesc->planstate);
/*
- * shutdown receiver
+ * shutdown tuple receiver, if we started it
*/
- (*destfunc->cleanup) (destfunc);
+ if (sendTuples)
+ (*dest->rShutdown) (dest);
- return result;
+ if (queryDesc->totaltime)
+ InstrStopNode(queryDesc->totaltime, estate->es_processed);
+
+ MemoryContextSwitchTo(oldcontext);
}
/* ----------------------------------------------------------------
- * ExecutorEnd
+ * ExecutorFinish
+ *
+ * This routine must be called after the last ExecutorRun call.
+ * It performs cleanup such as firing AFTER triggers. It is
+ * separate from ExecutorEnd because EXPLAIN ANALYZE needs to
+ * include these actions in the total runtime.
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ExecutorFinish is called. Such a plugin would
+ * normally call standard_ExecutorFinish().
*
- * This routine must be called at the end of execution of any
- * query plan
* ----------------------------------------------------------------
*/
void
-ExecutorEnd(QueryDesc *queryDesc, EState *estate)
+ExecutorFinish(QueryDesc *queryDesc)
+{
+ if (ExecutorFinish_hook)
+ (*ExecutorFinish_hook) (queryDesc);
+ else
+ standard_ExecutorFinish(queryDesc);
+}
+
+void
+standard_ExecutorFinish(QueryDesc *queryDesc)
{
+ EState *estate;
+ MemoryContext oldcontext;
+
/* sanity checks */
Assert(queryDesc != NULL);
- EndPlan(queryDesc->plantree, estate);
+ estate = queryDesc->estate;
- if (estate->es_snapshot != NULL)
- {
- if (estate->es_snapshot->xcnt > 0)
- pfree(estate->es_snapshot->xip);
- pfree(estate->es_snapshot);
- estate->es_snapshot = NULL;
- }
+ Assert(estate != NULL);
+ Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
- if (estate->es_param_exec_vals != NULL)
- {
- pfree(estate->es_param_exec_vals);
- estate->es_param_exec_vals = NULL;
- }
-}
+ /* This should be run once and only once per Executor instance */
+ Assert(!estate->es_finished);
+ /* Switch into per-query memory context */
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
-/*
- * ExecCheckQueryPerms
- * Check access permissions for all relations referenced in a query.
+ /* Allow instrumentation of Executor overall runtime */
+ if (queryDesc->totaltime)
+ InstrStartNode(queryDesc->totaltime);
+
+ /* Run ModifyTable nodes to completion */
+ ExecPostprocessPlan(estate);
+
+ /* Execute queued AFTER triggers, unless told not to */
+ if (!(estate->es_top_eflags & EXEC_FLAG_SKIP_TRIGGERS))
+ AfterTriggerEndQuery(estate);
+
+ if (queryDesc->totaltime)
+ InstrStopNode(queryDesc->totaltime, 0);
+
+ MemoryContextSwitchTo(oldcontext);
+
+ estate->es_finished = true;
+}
+
+/* ----------------------------------------------------------------
+ * ExecutorEnd
+ *
+ * This routine must be called at the end of execution of any
+ * query plan
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ExecutorEnd is called. Such a plugin would
+ * normally call standard_ExecutorEnd().
+ *
+ * ----------------------------------------------------------------
*/
-static void
-ExecCheckQueryPerms(CmdType operation, Query *parseTree, Plan *plan)
+void
+ExecutorEnd(QueryDesc *queryDesc)
+{
+ if (ExecutorEnd_hook)
+ (*ExecutorEnd_hook) (queryDesc);
+ else
+ standard_ExecutorEnd(queryDesc);
+}
+
+void
+standard_ExecutorEnd(QueryDesc *queryDesc)
{
+ EState *estate;
+ MemoryContext oldcontext;
+
+ /* sanity checks */
+ Assert(queryDesc != NULL);
+
+ estate = queryDesc->estate;
+
+ Assert(estate != NULL);
+
/*
- * Check RTEs in the query's primary rangetable.
+ * Check that ExecutorFinish was called, unless in EXPLAIN-only mode. This
+ * Assert is needed because ExecutorFinish is new as of 9.1, and callers
+ * might forget to call it.
*/
- ExecCheckRTPerms(parseTree->rtable, operation);
+ Assert(estate->es_finished ||
+ (estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
/*
- * Search for subplans and APPEND nodes to check their rangetables.
+ * Switch into per-query memory context to run ExecEndPlan
*/
- ExecCheckPlanPerms(plan, parseTree->rtable, operation);
-}
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
-/*
- * ExecCheckPlanPerms
- * Recursively scan the plan tree to check access permissions in
- * subplans.
- */
-static void
-ExecCheckPlanPerms(Plan *plan, List *rangeTable, CmdType operation)
-{
- List *subp;
+ ExecEndPlan(queryDesc->planstate, estate);
- if (plan == NULL)
- return;
+ /* do away with our snapshots */
+ UnregisterSnapshot(estate->es_snapshot);
+ UnregisterSnapshot(estate->es_crosscheck_snapshot);
- /* Check subplans, which we assume are plain SELECT queries */
+ /*
+ * Must switch out of context before destroying it
+ */
+ MemoryContextSwitchTo(oldcontext);
- foreach(subp, plan->initPlan)
- {
- SubPlan *subplan = (SubPlan *) lfirst(subp);
+ /* Exit parallel mode, if it was required by the query. */
+ if (queryDesc->plannedstmt->parallelModeNeeded &&
+ !(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ ExitParallelMode();
- ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
- ExecCheckPlanPerms(subplan->plan, subplan->rtable, CMD_SELECT);
- }
- foreach(subp, plan->subPlan)
- {
- SubPlan *subplan = (SubPlan *) lfirst(subp);
+ /*
+ * Release EState and per-query memory context. This should release
+ * everything the executor has allocated.
+ */
+ FreeExecutorState(estate);
- ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
- ExecCheckPlanPerms(subplan->plan, subplan->rtable, CMD_SELECT);
- }
+ /* Reset queryDesc fields that no longer point to anything */
+ queryDesc->tupDesc = NULL;
+ queryDesc->estate = NULL;
+ queryDesc->planstate = NULL;
+ queryDesc->totaltime = NULL;
+}
- /* Check lower plan nodes */
+/* ----------------------------------------------------------------
+ * ExecutorRewind
+ *
+ * This routine may be called on an open queryDesc to rewind it
+ * to the start.
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorRewind(QueryDesc *queryDesc)
+{
+ EState *estate;
+ MemoryContext oldcontext;
- ExecCheckPlanPerms(plan->lefttree, rangeTable, operation);
- ExecCheckPlanPerms(plan->righttree, rangeTable, operation);
+ /* sanity checks */
+ Assert(queryDesc != NULL);
- /* Do node-type-specific checks */
+ estate = queryDesc->estate;
- switch (nodeTag(plan))
- {
- case T_SubqueryScan:
- {
- SubqueryScan *scan = (SubqueryScan *) plan;
- RangeTblEntry *rte;
+ Assert(estate != NULL);
- /* Recursively check the subquery */
- rte = rt_fetch(scan->scan.scanrelid, rangeTable);
- Assert(rte->rtekind == RTE_SUBQUERY);
- ExecCheckQueryPerms(operation, rte->subquery, scan->subplan);
- break;
- }
- case T_Append:
- {
- Append *app = (Append *) plan;
- List *appendplans;
+ /* It's probably not sensible to rescan updating queries */
+ Assert(queryDesc->operation == CMD_SELECT);
- foreach(appendplans, app->appendplans)
- {
- ExecCheckPlanPerms((Plan *) lfirst(appendplans),
- rangeTable,
- operation);
- }
- break;
- }
+ /*
+ * Switch into per-query memory context
+ */
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
- default:
- break;
- }
+ /*
+ * rescan plan
+ */
+ ExecReScan(queryDesc->planstate);
+
+ MemoryContextSwitchTo(oldcontext);
}
+
/*
* ExecCheckRTPerms
* Check access permissions for all relations listed in a range table.
+ *
+ * Returns true if permissions are adequate. Otherwise, throws an appropriate
+ * error if ereport_on_violation is true, or simply returns false otherwise.
+ *
+ * Note that this does NOT address row level security policies (aka: RLS). If
+ * rows will be returned to the user as a result of this permission check
+ * passing, then RLS also needs to be consulted (and check_enable_rls()).
+ *
+ * See rewrite/rowsecurity.c.
*/
-static void
-ExecCheckRTPerms(List *rangeTable, CmdType operation)
+bool
+ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation)
{
- List *lp;
+ ListCell *l;
+ bool result = true;
- foreach(lp, rangeTable)
+ foreach(l, rangeTable)
{
- RangeTblEntry *rte = lfirst(lp);
+ RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
- ExecCheckRTEPerms(rte, operation);
+ result = ExecCheckRTEPerms(rte);
+ if (!result)
+ {
+ Assert(rte->rtekind == RTE_RELATION);
+ if (ereport_on_violation)
+ aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
+ get_rel_name(rte->relid));
+ return false;
+ }
}
+
+ if (ExecutorCheckPerms_hook)
+ result = (*ExecutorCheckPerms_hook) (rangeTable,
+ ereport_on_violation);
+ return result;
}
/*
* ExecCheckRTEPerms
* Check access permissions for a single RTE.
*/
-static void
-ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation)
+static bool
+ExecCheckRTEPerms(RangeTblEntry *rte)
{
+ AclMode requiredPerms;
+ AclMode relPerms;
+ AclMode remainingPerms;
Oid relOid;
Oid userid;
- AclResult aclcheck_result;
-
- /*
- * Only plain-relation RTEs need to be checked here. Subquery RTEs
- * will be checked when ExecCheckPlanPerms finds the SubqueryScan node,
- * and function RTEs are checked by init_fcache when the function is
- * prepared for execution. Join and special RTEs need no checks.
- */
+
+ /*
+ * Only plain-relation RTEs need to be checked here. Function RTEs are
+ * checked by init_fcache when the function is prepared for execution.
+ * Join, subquery, and special RTEs need no checks.
+ */
if (rte->rtekind != RTE_RELATION)
- return;
+ return true;
+
+ /*
+ * No work if requiredPerms is empty.
+ */
+ requiredPerms = rte->requiredPerms;
+ if (requiredPerms == 0)
+ return true;
relOid = rte->relid;
/*
- * userid to check as: current user unless we have a setuid
- * indication.
+ * userid to check as: current user unless we have a setuid indication.
*
* Note: GetUserId() is presently fast enough that there's no harm in
- * calling it separately for each RTE. If that stops being true, we
- * could call it once in ExecCheckQueryPerms and pass the userid down
- * from there. But for now, no need for the extra clutter.
+ * calling it separately for each RTE. If that stops being true, we could
+ * call it once in ExecCheckRTPerms and pass the userid down from there.
+ * But for now, no need for the extra clutter.
*/
userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
-#define CHECK(MODE) pg_class_aclcheck(relOid, userid, MODE)
-
- if (rte->checkForRead)
+ /*
+ * 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);
+ remainingPerms = requiredPerms & ~relPerms;
+ if (remainingPerms != 0)
{
- aclcheck_result = CHECK(ACL_SELECT);
- if (aclcheck_result != ACLCHECK_OK)
- aclcheck_error(aclcheck_result, get_rel_name(relOid));
- }
+ int col = -1;
+
+ /*
+ * 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;
- if (rte->checkForWrite)
- {
/*
- * Note: write access in a SELECT context means SELECT FOR UPDATE.
- * Right now we don't distinguish that from true update as far as
- * permissions checks are concerned.
+ * 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.
*/
- switch (operation)
+ if (remainingPerms & ACL_SELECT)
{
- case CMD_INSERT:
- aclcheck_result = CHECK(ACL_INSERT);
- break;
- case CMD_SELECT:
- case CMD_UPDATE:
- aclcheck_result = CHECK(ACL_UPDATE);
- break;
- case CMD_DELETE:
- aclcheck_result = CHECK(ACL_DELETE);
- break;
- default:
- elog(ERROR, "ExecCheckRTEPerms: bogus operation %d",
- operation);
- aclcheck_result = ACLCHECK_OK; /* keep compiler quiet */
- break;
+ /*
+ * 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;
+ }
+
+ while ((col = bms_next_member(rte->selectedCols, col)) >= 0)
+ {
+ /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
+ AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
+
+ if (attno == 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, attno, userid,
+ ACL_SELECT) != ACLCHECK_OK)
+ return false;
+ }
+ }
}
- if (aclcheck_result != ACLCHECK_OK)
- aclcheck_error(aclcheck_result, get_rel_name(relOid));
+
+ /*
+ * Basically the same for the mod columns, for both INSERT and UPDATE
+ * privilege as specified by remainingPerms.
+ */
+ if (remainingPerms & ACL_INSERT && !ExecCheckRTEPermsModified(relOid,
+ userid,
+ rte->insertedCols,
+ ACL_INSERT))
+ return false;
+
+ if (remainingPerms & ACL_UPDATE && !ExecCheckRTEPermsModified(relOid,
+ userid,
+ rte->updatedCols,
+ ACL_UPDATE))
+ return false;
}
+ return true;
}
-
-/* ===============================================================
- * ===============================================================
- static routines follow
- * ===============================================================
- * ===============================================================
+/*
+ * ExecCheckRTEPermsModified
+ * Check INSERT or UPDATE access permissions for a single RTE (these
+ * are processed uniformly).
*/
-
-typedef struct execRowMark
+static bool
+ExecCheckRTEPermsModified(Oid relOid, Oid userid, Bitmapset *modifiedCols,
+ AclMode requiredPerms)
{
- Relation relation;
- Index rti;
- char resname[32];
-} execRowMark;
+ int col = -1;
+
+ /*
+ * When the query doesn't explicitly update 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 UPDATE.
+ */
+ if (bms_is_empty(modifiedCols))
+ {
+ if (pg_attribute_aclcheck_all(relOid, userid, requiredPerms,
+ ACLMASK_ANY) != ACLCHECK_OK)
+ return false;
+ }
+
+ while ((col = bms_next_member(modifiedCols, col)) >= 0)
+ {
+ /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
+ AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
+
+ if (attno == InvalidAttrNumber)
+ {
+ /* whole-row reference can't happen here */
+ elog(ERROR, "whole-row update is not implemented");
+ }
+ else
+ {
+ if (pg_attribute_aclcheck(relOid, attno, userid,
+ requiredPerms) != ACLCHECK_OK)
+ return false;
+ }
+ }
+ return true;
+}
-typedef struct evalPlanQual
+/*
+ * Check that the query does not imply any writes to non-temp tables;
+ * unless we're in parallel mode, in which case don't even allow writes
+ * to temp tables.
+ *
+ * Note: in a Hot Standby slave this would need to reject writes to temp
+ * tables just as we do in parallel mode; 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)
{
- Plan *plan;
- Index rti;
- EState estate;
- struct evalPlanQual *free;
-} evalPlanQual;
+ ListCell *l;
+
+ /*
+ * Fail if write permissions are requested in parallel mode for table
+ * (temp or non-temp), otherwise fail for 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));
+ }
+
+ if (plannedstmt->commandType != CMD_SELECT || plannedstmt->hasModifyingCTE)
+ PreventCommandIfParallelMode(CreateCommandTag((Node *) plannedstmt));
+}
+
/* ----------------------------------------------------------------
* InitPlan
* and start up the rule manager
* ----------------------------------------------------------------
*/
-static TupleDesc
-InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
+static void
+InitPlan(QueryDesc *queryDesc, int eflags)
{
- List *rangeTable;
- Relation intoRelationDesc;
+ 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.
- */
- ExecCheckQueryPerms(operation, parseTree, plan);
-
- /*
- * get information from query descriptor
+ * Do permissions checks
*/
- rangeTable = parseTree->rtable;
+ ExecCheckRTPerms(rangeTable, true);
/*
* initialize the node's execution state
*/
estate->es_range_table = rangeTable;
+ estate->es_plannedstmt = plannedstmt;
/*
- * if there is a result relation, initialize result relation stuff
+ * 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 (parseTree->resultRelation != 0 && operation != CMD_SELECT)
+ if (plannedstmt->resultRelations)
{
- List *resultRelations = parseTree->resultRelations;
- int numResultRelations;
+ List *resultRelations = plannedstmt->resultRelations;
+ int numResultRelations = list_length(resultRelations);
ResultRelInfo *resultRelInfos;
+ ResultRelInfo *resultRelInfo;
- if (resultRelations != NIL)
- {
- /*
- * Multiple result relations (due to inheritance)
- * parseTree->resultRelations identifies them all
- */
- ResultRelInfo *resultRelInfo;
-
- numResultRelations = length(resultRelations);
- resultRelInfos = (ResultRelInfo *)
- palloc(numResultRelations * sizeof(ResultRelInfo));
- resultRelInfo = resultRelInfos;
- while (resultRelations != NIL)
- {
- initResultRelInfo(resultRelInfo,
- lfirsti(resultRelations),
- rangeTable,
- operation);
- resultRelInfo++;
- resultRelations = lnext(resultRelations);
- }
- }
- else
+ resultRelInfos = (ResultRelInfo *)
+ palloc(numResultRelations * sizeof(ResultRelInfo));
+ resultRelInfo = resultRelInfos;
+ foreach(l, resultRelations)
{
- /*
- * Single result relation identified by
- * parseTree->resultRelation
- */
- numResultRelations = 1;
- resultRelInfos = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
- initResultRelInfo(resultRelInfos,
- parseTree->resultRelation,
- rangeTable,
- operation);
+ Index resultRelationIndex = lfirst_int(l);
+ Oid resultRelationOid;
+ Relation resultRelation;
+
+ resultRelationOid = getrelid(resultRelationIndex, rangeTable);
+ resultRelation = heap_open(resultRelationOid, RowExclusiveLock);
+ InitResultRelInfo(resultRelInfo,
+ resultRelation,
+ resultRelationIndex,
+ estate->es_instrument);
+ resultRelInfo++;
}
-
estate->es_result_relations = resultRelInfos;
estate->es_num_result_relations = numResultRelations;
- /* Initialize to first or only result rel */
- estate->es_result_relation_info = resultRelInfos;
+ /* es_result_relation_info is NULL except when within ModifyTable */
+ estate->es_result_relation_info = NULL;
}
else
{
}
/*
- * Have to lock relations selected for update
+ * Similarly, we have to lock relations selected FOR [KEY] UPDATE/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_rowMark = NIL;
- if (parseTree->rowMarks != NIL)
+ estate->es_rowMarks = NIL;
+ foreach(l, plannedstmt->rowMarks)
{
- List *l;
+ PlanRowMark *rc = (PlanRowMark *) lfirst(l);
+ Oid relid;
+ Relation relation;
+ ExecRowMark *erm;
+
+ /* ignore "parent" rowmarks; they are irrelevant at runtime */
+ if (rc->isParent)
+ continue;
+
+ /* get relation's OID (will produce InvalidOid if subquery) */
+ relid = getrelid(rc->rti, rangeTable);
- foreach(l, parseTree->rowMarks)
+ /*
+ * If you change the conditions under which rel locks are acquired
+ * here, be sure to adjust ExecOpenScanRelation to match.
+ */
+ switch (rc->markType)
{
- Index rti = lfirsti(l);
- Oid relid = getrelid(rti, rangeTable);
- Relation relation;
- execRowMark *erm;
-
- relation = heap_open(relid, RowShareLock);
- erm = (execRowMark *) palloc(sizeof(execRowMark));
- erm->relation = relation;
- erm->rti = rti;
- sprintf(erm->resname, "ctid%u", rti);
- estate->es_rowMark = lappend(estate->es_rowMark, erm);
+ case ROW_MARK_EXCLUSIVE:
+ case ROW_MARK_NOKEYEXCLUSIVE:
+ case ROW_MARK_SHARE:
+ case ROW_MARK_KEYSHARE:
+ relation = heap_open(relid, RowShareLock);
+ break;
+ case ROW_MARK_REFERENCE:
+ relation = heap_open(relid, AccessShareLock);
+ break;
+ case ROW_MARK_COPY:
+ /* no physical table access is required */
+ relation = NULL;
+ break;
+ default:
+ elog(ERROR, "unrecognized markType: %d", rc->markType);
+ relation = NULL; /* keep compiler quiet */
+ break;
}
+
+ /* Check that relation is a legal target for marking */
+ if (relation)
+ CheckValidRowMarkRel(relation, rc->markType);
+
+ erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
+ erm->relation = relation;
+ erm->relid = relid;
+ erm->rti = rc->rti;
+ erm->prti = rc->prti;
+ erm->rowmarkId = rc->rowmarkId;
+ erm->markType = rc->markType;
+ erm->strength = rc->strength;
+ erm->waitPolicy = rc->waitPolicy;
+ erm->ermActive = false;
+ ItemPointerSetInvalid(&(erm->curCtid));
+ erm->ermExtra = NULL;
+ 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.
+ * Initialize the executor's tuple table to empty.
+ */
+ estate->es_tupleTable = NIL;
+ estate->es_trig_tuple_slot = NULL;
+ estate->es_trig_oldtup_slot = NULL;
+ estate->es_trig_newtup_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)
{
- int nSlots = ExecCountSlotsNode(plan);
+ Plan *subplan = (Plan *) lfirst(l);
+ PlanState *subplanstate;
+ int sp_eflags;
- if (parseTree->resultRelations != NIL)
- nSlots += length(parseTree->resultRelations);
- else
- nSlots += 1;
- estate->es_tupleTable = ExecCreateTupleTable(nSlots);
- }
+ /*
+ * 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 | EXEC_FLAG_WITH_NO_DATA);
+ if (bms_is_member(i, plannedstmt->rewindPlanIDs))
+ sp_eflags |= EXEC_FLAG_REWIND;
- /* mark EvalPlanQual not active */
- estate->es_origPlan = plan;
- estate->es_evalPlanQual = NULL;
- estate->es_evTuple = NULL;
- estate->es_evTupleNull = NULL;
- estate->es_useEvalPlan = false;
+ 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.
+ * Initialize the private state information for all the nodes in the query
+ * tree. This opens files, allocates storage and leaves us ready to start
+ * processing tuples.
*/
- ExecInitNode(plan, estate, NULL);
+ 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 = ExecGetTupType(plan); /* tuple descriptor */
+ 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. UPDATE and
- * DELETE always need one, since there's always a junk 'ctid'
- * attribute present --- no need to look first.
+ * 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;
- List *tlist;
+ ListCell *tlist;
- switch (operation)
+ foreach(tlist, plan->targetlist)
{
- case CMD_SELECT:
- case CMD_INSERT:
- foreach(tlist, plan->targetlist)
- {
- TargetEntry *tle = (TargetEntry *) lfirst(tlist);
+ TargetEntry *tle = (TargetEntry *) lfirst(tlist);
- if (tle->resdom->resjunk)
- {
- junk_filter_needed = true;
- break;
- }
- }
- break;
- case CMD_UPDATE:
- case CMD_DELETE:
+ if (tle->resjunk)
+ {
junk_filter_needed = true;
break;
- default:
- break;
+ }
}
if (junk_filter_needed)
{
- /*
- * If there are multiple result relations, each one needs its
- * own junk filter. Note this is only possible for
- * UPDATE/DELETE, so we can't be fooled by some needing a
- * filter and some not.
- */
- if (parseTree->resultRelations != NIL)
- {
- List *subplans;
- ResultRelInfo *resultRelInfo;
-
- /* Top plan had better be an Append here. */
- Assert(IsA(plan, Append));
- Assert(((Append *) plan)->isTarget);
- subplans = ((Append *) plan)->appendplans;
- Assert(length(subplans) == estate->es_num_result_relations);
- resultRelInfo = estate->es_result_relations;
- while (subplans != NIL)
- {
- Plan *subplan = (Plan *) lfirst(subplans);
- JunkFilter *j;
-
- j = ExecInitJunkFilter(subplan->targetlist,
- ExecGetTupType(subplan),
- ExecAllocTableSlot(estate->es_tupleTable));
- resultRelInfo->ri_junkFilter = j;
- resultRelInfo++;
- subplans = lnext(subplans);
- }
+ JunkFilter *j;
- /*
- * Set active junkfilter too; at this point ExecInitAppend
- * has already selected an active result relation...
- */
- estate->es_junkFilter =
- estate->es_result_relation_info->ri_junkFilter;
- }
- else
- {
- /* Normal case with just one JunkFilter */
- JunkFilter *j;
-
- j = ExecInitJunkFilter(plan->targetlist,
- tupType,
- ExecAllocTableSlot(estate->es_tupleTable));
- estate->es_junkFilter = j;
- if (estate->es_result_relation_info)
- estate->es_result_relation_info->ri_junkFilter = j;
-
- /* For SELECT, want to return the cleaned tuple type */
- if (operation == CMD_SELECT)
- tupType = j->jf_cleanTupType;
- }
+ j = ExecInitJunkFilter(planstate->plan->targetlist,
+ tupType->tdhasoid,
+ ExecInitExtraTupleSlot(estate));
+ estate->es_junkFilter = j;
+
+ /* Want to return the cleaned tuple type */
+ tupType = j->jf_cleanTupType;
}
- else
- estate->es_junkFilter = NULL;
}
- /*
- * initialize the "into" relation
- */
- intoRelationDesc = (Relation) NULL;
+ queryDesc->tupDesc = tupType;
+ queryDesc->planstate = planstate;
+}
- if (operation == CMD_SELECT)
+/*
+ * Check that a proposed result relation is a legal target for the operation
+ *
+ * Generally the parser and/or planner should have noticed any such mistake
+ * already, but let's make sure.
+ *
+ * Note: when changing this function, you probably also need to look at
+ * CheckValidRowMarkRel.
+ */
+void
+CheckValidResultRel(Relation resultRel, CmdType operation)
+{
+ TriggerDesc *trigDesc = resultRel->trigdesc;
+ FdwRoutine *fdwroutine;
+
+ switch (resultRel->rd_rel->relkind)
{
- if (!parseTree->isPortal)
- {
+ case RELKIND_RELATION:
+ /* OK */
+ break;
+ case RELKIND_SEQUENCE:
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot change sequence \"%s\"",
+ RelationGetRelationName(resultRel))));
+ break;
+ case RELKIND_TOASTVALUE:
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot change TOAST relation \"%s\"",
+ RelationGetRelationName(resultRel))));
+ break;
+ case RELKIND_VIEW:
+
/*
- * a select into table --- need to create the "into" table
+ * Okay only if there's a suitable INSTEAD OF trigger. Messages
+ * here should match rewriteHandler.c's rewriteTargetView, except
+ * that we omit errdetail because we haven't got the information
+ * handy (and given that we really shouldn't get here anyway, it's
+ * not worth great exertion to get).
*/
- if (parseTree->into != NULL)
+ switch (operation)
{
- char *intoName;
- Oid namespaceId;
- Oid intoRelationId;
- TupleDesc tupdesc;
-
- /*
- * find namespace to create in, check permissions
- */
- intoName = parseTree->into->relname;
- namespaceId = RangeVarGetCreationNamespace(parseTree->into);
-
- if (!isTempNamespace(namespaceId))
- {
- AclResult aclresult;
-
- aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
- ACL_CREATE);
- if (aclresult != ACLCHECK_OK)
- aclcheck_error(aclresult,
- get_namespace_name(namespaceId));
- }
-
- /*
- * have to copy tupType to get rid of constraints
- */
- tupdesc = CreateTupleDescCopy(tupType);
-
- intoRelationId =
- heap_create_with_catalog(intoName,
- namespaceId,
- tupdesc,
- RELKIND_RELATION,
- false,
- 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.
- */
- AlterTableCreateToastTable(intoRelationId, true);
-
- intoRelationDesc = heap_open(intoRelationId,
- AccessExclusiveLock);
+ case CMD_INSERT:
+ if (!trigDesc || !trigDesc->trig_insert_instead_row)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot insert into view \"%s\"",
+ RelationGetRelationName(resultRel)),
+ errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
+ break;
+ case CMD_UPDATE:
+ if (!trigDesc || !trigDesc->trig_update_instead_row)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot update view \"%s\"",
+ RelationGetRelationName(resultRel)),
+ errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
+ break;
+ case CMD_DELETE:
+ if (!trigDesc || !trigDesc->trig_delete_instead_row)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot delete from view \"%s\"",
+ RelationGetRelationName(resultRel)),
+ errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
+ break;
+ default:
+ elog(ERROR, "unrecognized CmdType: %d", (int) operation);
+ break;
}
- }
+ break;
+ case RELKIND_MATVIEW:
+ if (!MatViewIncrementalMaintenanceIsEnabled())
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot change materialized view \"%s\"",
+ RelationGetRelationName(resultRel))));
+ break;
+ case RELKIND_FOREIGN_TABLE:
+ /* Okay only if the FDW supports it */
+ fdwroutine = GetFdwRoutineForRelation(resultRel, false);
+ switch (operation)
+ {
+ case CMD_INSERT:
+ if (fdwroutine->ExecForeignInsert == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot insert into foreign table \"%s\"",
+ RelationGetRelationName(resultRel))));
+ if (fdwroutine->IsForeignRelUpdatable != NULL &&
+ (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_INSERT)) == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("foreign table \"%s\" does not allow inserts",
+ RelationGetRelationName(resultRel))));
+ break;
+ case CMD_UPDATE:
+ if (fdwroutine->ExecForeignUpdate == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot update foreign table \"%s\"",
+ RelationGetRelationName(resultRel))));
+ if (fdwroutine->IsForeignRelUpdatable != NULL &&
+ (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_UPDATE)) == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("foreign table \"%s\" does not allow updates",
+ RelationGetRelationName(resultRel))));
+ break;
+ case CMD_DELETE:
+ if (fdwroutine->ExecForeignDelete == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot delete from foreign table \"%s\"",
+ RelationGetRelationName(resultRel))));
+ if (fdwroutine->IsForeignRelUpdatable != NULL &&
+ (fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_DELETE)) == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("foreign table \"%s\" does not allow deletes",
+ RelationGetRelationName(resultRel))));
+ break;
+ default:
+ elog(ERROR, "unrecognized CmdType: %d", (int) operation);
+ break;
+ }
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot change relation \"%s\"",
+ RelationGetRelationName(resultRel))));
+ break;
}
-
- estate->es_into_relation_descriptor = intoRelationDesc;
-
- return tupType;
}
/*
- * Initialize ResultRelInfo data for one result relation
+ * Check that a proposed rowmark target relation is a legal target
+ *
+ * In most cases parser and/or planner should have noticed this already, but
+ * they don't cover all cases.
*/
static void
-initResultRelInfo(ResultRelInfo *resultRelInfo,
- Index resultRelationIndex,
- List *rangeTable,
- CmdType operation)
+CheckValidRowMarkRel(Relation rel, RowMarkType markType)
{
- Oid resultRelationOid;
- Relation resultRelationDesc;
+ FdwRoutine *fdwroutine;
- resultRelationOid = getrelid(resultRelationIndex, rangeTable);
- resultRelationDesc = heap_open(resultRelationOid, RowExclusiveLock);
-
- switch (resultRelationDesc->rd_rel->relkind)
+ switch (rel->rd_rel->relkind)
{
+ case RELKIND_RELATION:
+ /* OK */
+ break;
case RELKIND_SEQUENCE:
- elog(ERROR, "You can't change sequence relation %s",
- RelationGetRelationName(resultRelationDesc));
+ /* Must disallow this because we don't vacuum sequences */
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot lock rows in sequence \"%s\"",
+ RelationGetRelationName(rel))));
break;
case RELKIND_TOASTVALUE:
- elog(ERROR, "You can't change toast relation %s",
- RelationGetRelationName(resultRelationDesc));
+ /* We could allow this, but there seems no good reason to */
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot lock rows in TOAST relation \"%s\"",
+ RelationGetRelationName(rel))));
break;
case RELKIND_VIEW:
- elog(ERROR, "You can't change view relation %s",
- RelationGetRelationName(resultRelationDesc));
+ /* Should not get here; planner should have expanded the view */
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot lock rows in view \"%s\"",
+ RelationGetRelationName(rel))));
+ break;
+ case RELKIND_MATVIEW:
+ /* Allow referencing a matview, but not actual locking clauses */
+ if (markType != ROW_MARK_REFERENCE)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot lock rows in materialized view \"%s\"",
+ RelationGetRelationName(rel))));
+ break;
+ case RELKIND_FOREIGN_TABLE:
+ /* Okay only if the FDW supports it */
+ fdwroutine = GetFdwRoutineForRelation(rel, false);
+ if (fdwroutine->RefetchForeignRow == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot lock rows in foreign table \"%s\"",
+ RelationGetRelationName(rel))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("cannot lock rows in relation \"%s\"",
+ RelationGetRelationName(rel))));
break;
}
+}
+/*
+ * Initialize ResultRelInfo data for one result relation
+ *
+ * Caution: before Postgres 9.1, this function included the relkind checking
+ * that's now in CheckValidResultRel, and it also did ExecOpenIndices if
+ * appropriate. Be sure callers cover those needs.
+ */
+void
+InitResultRelInfo(ResultRelInfo *resultRelInfo,
+ Relation resultRelationDesc,
+ Index resultRelationIndex,
+ int instrument_options)
+{
MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
resultRelInfo->type = T_ResultRelInfo;
resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
resultRelInfo->ri_NumIndices = 0;
resultRelInfo->ri_IndexRelationDescs = NULL;
resultRelInfo->ri_IndexRelationInfo = NULL;
- resultRelInfo->ri_TrigDesc = resultRelationDesc->trigdesc;
- resultRelInfo->ri_TrigFunctions = 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;
+ }
+ if (resultRelationDesc->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ resultRelInfo->ri_FdwRoutine = GetFdwRoutineForRelation(resultRelationDesc, true);
+ else
+ resultRelInfo->ri_FdwRoutine = NULL;
+ resultRelInfo->ri_FdwState = NULL;
resultRelInfo->ri_ConstraintExprs = NULL;
resultRelInfo->ri_junkFilter = NULL;
+ resultRelInfo->ri_projectReturning = NULL;
+}
+
+/*
+ * 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. Also, we need not
+ * recheck the relkind, so no need for CheckValidResultRel.
+ */
+ rel = heap_open(relid, NoLock);
+
+ /*
+ * Make the new entry in the right context.
+ */
+ oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+ rInfo = makeNode(ResultRelInfo);
+ InitResultRelInfo(rInfo,
+ rel,
+ 0, /* dummy rangetable index */
+ estate->es_instrument);
+ estate->es_trig_target_relations =
+ lappend(estate->es_trig_target_relations, rInfo);
+ MemoryContextSwitchTo(oldcontext);
+
+ /*
+ * Currently, we don't need any index information in ResultRelInfos used
+ * only for triggers, so no need to call ExecOpenIndices.
+ */
+
+ return rInfo;
+}
+
+/*
+ * ExecContextForcesOids
+ *
+ * This is pretty grotty: when doing INSERT, UPDATE, or CREATE TABLE AS,
+ * 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.
+ *
+ * CREATE TABLE AS is even uglier, because we don't have the target relation's
+ * descriptor available when this code runs; we have to look aside at the
+ * flags passed to ExecutorStart().
+ */
+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_top_eflags & EXEC_FLAG_WITH_OIDS)
+ {
+ *hasoids = true;
+ return true;
+ }
+ if (planstate->state->es_top_eflags & EXEC_FLAG_WITHOUT_OIDS)
+ {
+ *hasoids = false;
+ return true;
+ }
+
+ return false;
+}
+
+/* ----------------------------------------------------------------
+ * ExecPostprocessPlan
+ *
+ * Give plan nodes a final chance to execute before shutdown
+ * ----------------------------------------------------------------
+ */
+static void
+ExecPostprocessPlan(EState *estate)
+{
+ ListCell *lc;
+
+ /*
+ * Make sure nodes run forward.
+ */
+ estate->es_direction = ForwardScanDirection;
/*
- * 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.
+ * Run any secondary ModifyTable nodes to completion, in case the main
+ * query did not fetch all rows from them. (We do this to ensure that
+ * such nodes have predictable results.)
*/
- if (resultRelationDesc->rd_rel->relhasindex &&
- operation != CMD_DELETE)
- ExecOpenIndices(resultRelInfo);
+ foreach(lc, estate->es_auxmodifytables)
+ {
+ PlanState *ps = (PlanState *) lfirst(lc);
+
+ for (;;)
+ {
+ TupleTableSlot *slot;
+
+ /* Reset the per-output-tuple exprcontext each time */
+ ResetPerTupleExprContext(estate);
+
+ slot = ExecProcNode(ps);
+
+ if (TupIsNull(slot))
+ break;
+ }
+ }
}
/* ----------------------------------------------------------------
- * EndPlan
+ * ExecEndPlan
+ *
+ * Cleans up the query plan -- closes files and frees up storage
*
- * Cleans up the query plan -- closes files and free up storages
+ * 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
-EndPlan(Plan *plan, EState *estate)
+ExecEndPlan(PlanState *planstate, EState *estate)
{
ResultRelInfo *resultRelInfo;
int i;
- List *l;
+ ListCell *l;
/*
- * shut down any PlanQual processing we were doing
+ * shut down the node-type-specific query processing
*/
- if (estate->es_evalPlanQual != NULL)
- EndEvalPlanQual(estate);
+ ExecEndNode(planstate);
/*
- * shut down the node-type-specific query processing
+ * for subplans too
*/
- ExecEndNode(plan, NULL);
+ foreach(l, estate->es_subplanstates)
+ {
+ PlanState *subplanstate = (PlanState *) lfirst(l);
+
+ ExecEndNode(subplanstate);
+ }
/*
- * destroy the executor "tuple" table.
+ * 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.
*/
- ExecDropTupleTable(estate->es_tupleTable, true);
- estate->es_tupleTable = NULL;
+ ExecResetTupleTable(estate->es_tupleTable, false);
/*
- * close the result relation(s) if any, but hold locks until xact
- * commit. Also clean up junkfilters if present.
+ * 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);
- /* Delete the junkfilter if any */
- if (resultRelInfo->ri_junkFilter != NULL)
- ExecFreeJunkFilter(resultRelInfo->ri_junkFilter);
resultRelInfo++;
}
/*
- * close the "into" relation if necessary, again keeping lock
- */
- if (estate->es_into_relation_descriptor != NULL)
- heap_close(estate->es_into_relation_descriptor, NoLock);
-
- /*
- * There might be a junkfilter without a result relation.
+ * likewise close any trigger target relations
*/
- if (estate->es_num_result_relations == 0 &&
- estate->es_junkFilter != NULL)
+ foreach(l, estate->es_trig_target_relations)
{
- ExecFreeJunkFilter(estate->es_junkFilter);
- estate->es_junkFilter = NULL;
+ 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, again keeping locks
+ * close any relations selected FOR [KEY] UPDATE/SHARE, again keeping
+ * locks
*/
- foreach(l, estate->es_rowMark)
+ foreach(l, estate->es_rowMarks)
{
- execRowMark *erm = lfirst(l);
+ ExecRowMark *erm = (ExecRowMark *) lfirst(l);
- heap_close(erm->relation, NoLock);
+ if (erm->relation)
+ 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
+ * Processes the query plan until we have retrieved 'numberTuples' tuples,
+ * moving in the specified direction.
*
- * result is either a slot containing the last tuple in the case
- * of a SELECT or NULL otherwise.
+ * 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 TupleTableSlot *
+static void
ExecutePlan(EState *estate,
- Plan *plan,
+ PlanState *planstate,
CmdType operation,
+ bool sendTuples,
long numberTuples,
ScanDirection direction,
- DestReceiver *destfunc)
+ DestReceiver *dest)
{
- JunkFilter *junkfilter;
TupleTableSlot *slot;
- ItemPointer tupleid = NULL;
- ItemPointerData tuple_ctid;
long current_tuple_count;
- TupleTableSlot *result;
/*
* initialize local variables
*/
- slot = NULL;
current_tuple_count = 0;
- result = NULL;
/*
* Set the direction.
estate->es_direction = direction;
/*
- * Loop until we've processed the proper number of tuples from the
- * plan.
+ * Loop until we've processed the proper number of tuples from the plan.
*/
-
for (;;)
{
/* Reset the per-output-tuple exprcontext */
/*
* Execute the plan and obtain a tuple
*/
-lnext: ;
- if (estate->es_useEvalPlan)
- {
- slot = EvalPlanQualNext(estate);
- if (TupIsNull(slot))
- slot = ExecProcNode(plan, NULL);
- }
- else
- slot = ExecProcNode(plan, NULL);
+ slot = ExecProcNode(planstate);
/*
* if the tuple is null, then we assume there is nothing more to
- * process so we just return null...
+ * process so we just end the loop...
*/
if (TupIsNull(slot))
- {
- result = NULL;
break;
- }
/*
- * if we have a junk filter, then project a new tuple with the
- * junk removed.
+ * 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.
+ * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
+ * because that tuple slot has the wrong descriptor.)
*/
- if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL)
- {
- Datum datum;
- HeapTuple newTuple;
- bool isNull;
-
- /*
- * extract the 'ctid' junk attribute.
- */
- if (operation == CMD_UPDATE || operation == CMD_DELETE)
- {
- if (!ExecGetJunkAttribute(junkfilter,
- slot,
- "ctid",
- &datum,
- &isNull))
- elog(ERROR, "ExecutePlan: NO (junk) `ctid' was found!");
-
- /* shouldn't ever get a null result... */
- if (isNull)
- elog(ERROR, "ExecutePlan: (junk) `ctid' is NULL!");
-
- tupleid = (ItemPointer) DatumGetPointer(datum);
- tuple_ctid = *tupleid; /* make sure we don't free the
- * ctid!! */
- tupleid = &tuple_ctid;
- }
- else if (estate->es_rowMark != NIL)
- {
- List *l;
-
- lmark: ;
- foreach(l, estate->es_rowMark)
- {
- execRowMark *erm = lfirst(l);
- Buffer buffer;
- HeapTupleData tuple;
- TupleTableSlot *newSlot;
- int test;
-
- if (!ExecGetJunkAttribute(junkfilter,
- slot,
- erm->resname,
- &datum,
- &isNull))
- elog(ERROR, "ExecutePlan: NO (junk) `%s' was found!",
- erm->resname);
-
- /* shouldn't ever get a null result... */
- if (isNull)
- elog(ERROR, "ExecutePlan: (junk) `%s' is NULL!",
- erm->resname);
-
- tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
- test = heap_mark4update(erm->relation, &tuple, &buffer,
- estate->es_snapshot->curcid);
- ReleaseBuffer(buffer);
- switch (test)
- {
- case HeapTupleSelfUpdated:
- case HeapTupleMayBeUpdated:
- break;
-
- case HeapTupleUpdated:
- if (XactIsoLevel == XACT_SERIALIZABLE)
- elog(ERROR, "Can't serialize access due to concurrent update");
- if (!(ItemPointerEquals(&(tuple.t_self),
- (ItemPointer) DatumGetPointer(datum))))
- {
- newSlot = EvalPlanQual(estate, erm->rti, &(tuple.t_self));
- if (!(TupIsNull(newSlot)))
- {
- slot = newSlot;
- estate->es_useEvalPlan = true;
- goto lmark;
- }
- }
-
- /*
- * if tuple was deleted or PlanQual failed for
- * updated tuple - we must not return this
- * tuple!
- */
- goto lnext;
-
- default:
- elog(ERROR, "Unknown status %u from heap_mark4update", test);
- return (NULL);
- }
- }
- }
-
- /*
- * Finally create a new "clean" tuple with all junk attributes
- * removed
- */
- newTuple = ExecRemoveJunk(junkfilter, slot);
-
- slot = ExecStoreTuple(newTuple, /* tuple to store */
- junkfilter->jf_resultSlot, /* dest slot */
- InvalidBuffer, /* this tuple has no buffer */
- true); /* tuple should be pfreed */
- }
+ if (estate->es_junkFilter != NULL)
+ slot = ExecFilterJunk(estate->es_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.
+ * If we are supposed to send the tuple somewhere, do so. (In
+ * practice, this is probably always the case at this point.)
*/
- switch (operation)
- {
- case CMD_SELECT:
- ExecSelect(slot, /* slot containing tuple */
- destfunc, /* destination's tuple-receiver obj */
- estate);
- result = slot;
- break;
-
- case CMD_INSERT:
- ExecInsert(slot, tupleid, estate);
- result = NULL;
- break;
-
- case CMD_DELETE:
- ExecDelete(slot, tupleid, estate);
- result = NULL;
- break;
-
- case CMD_UPDATE:
- ExecUpdate(slot, tupleid, estate);
- result = NULL;
- break;
+ if (sendTuples)
+ (*dest->receiveSlot) (slot, dest);
- default:
- elog(LOG, "ExecutePlan: unknown operation in queryDesc");
- result = NULL;
- break;
- }
+ /*
+ * 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..
+ * 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 == current_tuple_count)
+ if (numberTuples && numberTuples == current_tuple_count)
break;
}
-
- /*
- * here, result is either a slot containing a tuple in the case of a
- * SELECT or NULL otherwise.
- */
- return result;
}
-/* ----------------------------------------------------------------
- * ExecSelect
+
+/*
+ * ExecRelCheck --- check that tuple meets constraints for result relation
*
- * SELECTs are easy.. we just pass the tuple to the appropriate
- * print function. The only complexity is when we do a
- * "SELECT INTO", in which case we insert the tuple into
- * the appropriate relation (note: this is a newly created relation
- * so we don't need to worry about indices or locks.)
- * ----------------------------------------------------------------
+ * Returns NULL if OK, else name of failed check constraint
*/
-static void
-ExecSelect(TupleTableSlot *slot,
- DestReceiver *destfunc,
- EState *estate)
+static const char *
+ExecRelCheck(ResultRelInfo *resultRelInfo,
+ TupleTableSlot *slot, EState *estate)
{
- HeapTuple tuple;
- TupleDesc attrtype;
+ 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;
/*
- * get the heap tuple out of the tuple table slot
+ * 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.
*/
- tuple = slot->val;
- attrtype = slot->ttc_tupleDescriptor;
-
- /*
- * insert the tuple into the "into relation"
- */
- if (estate->es_into_relation_descriptor != NULL)
+ if (resultRelInfo->ri_ConstraintExprs == NULL)
{
- heap_insert(estate->es_into_relation_descriptor, tuple,
- estate->es_snapshot->curcid);
- IncrAppended();
+ 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);
}
/*
- * send the tuple to the front end (or the screen)
+ * We will use the EState's per-tuple context for evaluating constraint
+ * expressions (creating it if it's not already there).
*/
- (*destfunc->receiveTuple) (tuple, attrtype, destfunc);
- IncrRetrieved();
- (estate->es_processed)++;
-}
+ econtext = GetPerTupleExprContext(estate);
-/* ----------------------------------------------------------------
- * 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,
- EState *estate)
-{
- HeapTuple tuple;
- ResultRelInfo *resultRelInfo;
- Relation resultRelationDesc;
- int numIndices;
- Oid newId;
+ /* Arrange for econtext's scan tuple to be the tuple under test */
+ econtext->ecxt_scantuple = slot;
- /*
- * get the heap tuple out of the tuple table slot
- */
- tuple = slot->val;
+ /* And evaluate the constraints */
+ for (i = 0; i < ncheck; i++)
+ {
+ qual = resultRelInfo->ri_ConstraintExprs[i];
- /*
- * get information on the (current) result relation
- */
- resultRelInfo = estate->es_result_relation_info;
- resultRelationDesc = resultRelInfo->ri_RelationDesc;
+ /*
+ * NOTE: SQL 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;
+ }
- /* BEFORE ROW INSERT Triggers */
- if (resultRelInfo->ri_TrigDesc &&
- resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
- {
- HeapTuple newtuple;
+ /* NULL result means no error */
+ return NULL;
+}
+
+void
+ExecConstraints(ResultRelInfo *resultRelInfo,
+ TupleTableSlot *slot, EState *estate)
+{
+ Relation rel = resultRelInfo->ri_RelationDesc;
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ TupleConstr *constr = tupdesc->constr;
+ Bitmapset *modifiedCols;
+ Bitmapset *insertedCols;
+ Bitmapset *updatedCols;
- newtuple = ExecBRInsertTriggers(estate, resultRelInfo, tuple);
+ Assert(constr);
- if (newtuple == NULL) /* "do nothing" */
- return;
+ if (constr->has_not_null)
+ {
+ int natts = tupdesc->natts;
+ int attrChk;
- if (newtuple != tuple) /* modified by Trigger(s) */
+ for (attrChk = 1; attrChk <= natts; attrChk++)
{
- /*
- * Insert modified tuple into tuple table slot, replacing the
- * original. We assume that it was allocated in per-tuple
- * memory context, and therefore will go away by itself. The
- * tuple table slot should not try to clear it.
- */
- ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
- tuple = newtuple;
+ if (tupdesc->attrs[attrChk - 1]->attnotnull &&
+ slot_attisnull(slot, attrChk))
+ {
+ char *val_desc;
+
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
+
+ ereport(ERROR,
+ (errcode(ERRCODE_NOT_NULL_VIOLATION),
+ errmsg("null value in column \"%s\" violates not-null constraint",
+ NameStr(tupdesc->attrs[attrChk - 1]->attname)),
+ val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+ errtablecol(rel, attrChk)));
+ }
}
}
- /*
- * Check the constraints of the tuple
- */
- if (resultRelationDesc->rd_att->constr)
- ExecConstraints("ExecInsert", resultRelInfo, slot, estate);
-
- /*
- * insert the tuple
- */
- newId = heap_insert(resultRelationDesc, tuple,
- estate->es_snapshot->curcid);
-
- IncrAppended();
- (estate->es_processed)++;
- estate->es_lastoid = newId;
- setLastTid(&(tuple->t_self));
-
- /*
- * process indices
- *
- * Note: heap_insert adds a new tuple to a relation. As a side effect,
- * the tupleid of the new tuple is placed in the new tuple's t_ctid
- * field.
- */
- numIndices = resultRelInfo->ri_NumIndices;
- if (numIndices > 0)
- ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
+ if (constr->num_check > 0)
+ {
+ const char *failed;
- /* AFTER ROW INSERT Triggers */
- if (resultRelInfo->ri_TrigDesc)
- ExecARInsertTriggers(estate, resultRelInfo, tuple);
+ if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
+ {
+ char *val_desc;
+
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
+ ereport(ERROR,
+ (errcode(ERRCODE_CHECK_VIOLATION),
+ errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
+ RelationGetRelationName(rel), failed),
+ val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+ errtableconstraint(rel, failed)));
+ }
+ }
}
-/* ----------------------------------------------------------------
- * ExecDelete
+/*
+ * ExecWithCheckOptions -- check that tuple satisfies any WITH CHECK OPTIONs
+ * of the specified kind.
*
- * DELETE is like UPDATE, we delete the tuple and its
- * index tuples.
- * ----------------------------------------------------------------
+ * Note that this needs to be called multiple times to ensure that all kinds of
+ * WITH CHECK OPTIONs are handled (both those from views which have the WITH
+ * CHECK OPTION set and from row level security policies). See ExecInsert()
+ * and ExecUpdate().
*/
-static void
-ExecDelete(TupleTableSlot *slot,
- ItemPointer tupleid,
- EState *estate)
+void
+ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
+ TupleTableSlot *slot, EState *estate)
{
- ResultRelInfo *resultRelInfo;
- Relation resultRelationDesc;
- ItemPointerData ctid;
- int result;
+ Relation rel = resultRelInfo->ri_RelationDesc;
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ ExprContext *econtext;
+ ListCell *l1,
+ *l2;
/*
- * get information on the (current) result relation
+ * We will use the EState's per-tuple context for evaluating constraint
+ * expressions (creating it if it's not already there).
*/
- 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);
+ econtext = GetPerTupleExprContext(estate);
- if (!dodelete) /* "do nothing" */
- return;
- }
+ /* Arrange for econtext's scan tuple to be the tuple under test */
+ econtext->ecxt_scantuple = slot;
- /*
- * delete the tuple
- */
-ldelete:;
- result = heap_delete(resultRelationDesc, tupleid,
- &ctid,
- estate->es_snapshot->curcid);
- switch (result)
+ /* Check each of the constraints */
+ forboth(l1, resultRelInfo->ri_WithCheckOptions,
+ l2, resultRelInfo->ri_WithCheckOptionExprs)
{
- case HeapTupleSelfUpdated:
- return;
+ WithCheckOption *wco = (WithCheckOption *) lfirst(l1);
+ ExprState *wcoExpr = (ExprState *) lfirst(l2);
- case HeapTupleMayBeUpdated:
- break;
+ /*
+ * Skip any WCOs which are not the kind we are looking for at this
+ * time.
+ */
+ if (wco->kind != kind)
+ continue;
- case HeapTupleUpdated:
- if (XactIsoLevel == XACT_SERIALIZABLE)
- elog(ERROR, "Can't serialize access due to concurrent update");
- else if (!(ItemPointerEquals(tupleid, &ctid)))
- {
- TupleTableSlot *epqslot = EvalPlanQual(estate,
- resultRelInfo->ri_RangeTableIndex, &ctid);
+ /*
+ * WITH CHECK OPTION checks are intended to ensure that the new tuple
+ * is visible (in the case of a view) or that it passes the
+ * 'with-check' policy (in the case of row security). If the qual
+ * evaluates to NULL or FALSE, then the new tuple won't be included in
+ * the view or doesn't pass the 'with-check' policy for the table. We
+ * need ExecQual to return FALSE for NULL to handle the view case (the
+ * opposite of what we do above for CHECK constraints).
+ */
+ if (!ExecQual((List *) wcoExpr, econtext, false))
+ {
+ char *val_desc;
+ Bitmapset *modifiedCols;
+ Bitmapset *insertedCols;
+ Bitmapset *updatedCols;
- if (!TupIsNull(epqslot))
- {
- *tupleid = ctid;
- goto ldelete;
- }
+ switch (wco->kind)
+ {
+ /*
+ * For WITH CHECK OPTIONs coming from views, we might be
+ * able to provide the details on the row, depending on
+ * the permissions on the relation (that is, if the user
+ * could view it directly anyway). For RLS violations, we
+ * don't include the data since we don't know if the user
+ * should be able to view the tuple as as that depends on
+ * the USING policy.
+ */
+ case WCO_VIEW_CHECK:
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
+
+ ereport(ERROR,
+ (errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
+ errmsg("new row violates WITH CHECK OPTION for \"%s\"",
+ wco->relname),
+ val_desc ? errdetail("Failing row contains %s.",
+ val_desc) : 0));
+ break;
+ case WCO_RLS_INSERT_CHECK:
+ case WCO_RLS_UPDATE_CHECK:
+ if (wco->polname != NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy \"%s\" for \"%s\"",
+ wco->polname, wco->relname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy for \"%s\"",
+ wco->relname)));
+ break;
+ case WCO_RLS_CONFLICT_CHECK:
+ if (wco->polname != NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy \"%s\" (USING expression) for \"%s\"",
+ wco->polname, wco->relname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy (USING expression) for \"%s\"",
+ wco->relname)));
+ break;
+ default:
+ elog(ERROR, "unrecognized WCO kind: %u", wco->kind);
+ break;
}
- /* tuple already deleted; nothing to do */
- return;
-
- default:
- elog(ERROR, "Unknown status %u from heap_delete", result);
- return;
+ }
}
+}
- IncrDeleted();
- (estate->es_processed)++;
+/*
+ * ExecBuildSlotValueDescription -- construct a string representing a tuple
+ *
+ * This is intentionally very similar to BuildIndexValueDescription, but
+ * unlike that function, we truncate long field values (to at most maxfieldlen
+ * bytes). That seems necessary here since heap field values could be very
+ * long, whereas index entries typically aren't so wide.
+ *
+ * Also, unlike the case with index entries, we need to be prepared to ignore
+ * dropped columns. We used to use the slot's tuple descriptor to decode the
+ * data, but the slot's descriptor doesn't identify dropped columns, so we
+ * now need to be passed the relation's descriptor.
+ *
+ * Note that, like BuildIndexValueDescription, if the user does not have
+ * permission to view any of the columns involved, a NULL is returned. Unlike
+ * BuildIndexValueDescription, if the user has access to view a subset of the
+ * column involved, that subset will be returned with a key identifying which
+ * columns they are.
+ */
+static char *
+ExecBuildSlotValueDescription(Oid reloid,
+ TupleTableSlot *slot,
+ TupleDesc tupdesc,
+ Bitmapset *modifiedCols,
+ int maxfieldlen)
+{
+ StringInfoData buf;
+ StringInfoData collist;
+ bool write_comma = false;
+ bool write_comma_collist = false;
+ int i;
+ AclResult aclresult;
+ bool table_perm = false;
+ bool any_perm = false;
/*
- * Note: Normally one would think that we have to delete index tuples
- * associated with the heap tuple now..
- *
- * ... but in POSTGRES, we have no need to do this because the vacuum
- * daemon automatically opens an index scan and deletes index tuples
- * when it finds deleted heap tuples. -cim 9/27/89
+ * Check if RLS is enabled and should be active for the relation; if so,
+ * then don't return anything. Otherwise, go through normal permission
+ * checks.
*/
+ if (check_enable_rls(reloid, InvalidOid, true) == RLS_ENABLED)
+ return NULL;
- /* AFTER ROW DELETE Triggers */
- if (resultRelInfo->ri_TrigDesc)
- ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
-}
+ initStringInfo(&buf);
-/* ----------------------------------------------------------------
- * 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,
- EState *estate)
-{
- HeapTuple tuple;
- ResultRelInfo *resultRelInfo;
- Relation resultRelationDesc;
- ItemPointerData ctid;
- int result;
- int numIndices;
+ appendStringInfoChar(&buf, '(');
/*
- * abort the operation if not running transactions
+ * Check if the user has permissions to see the row. Table-level SELECT
+ * allows access to all columns. If the user does not have table-level
+ * SELECT then we check each column and include those the user has SELECT
+ * rights on. Additionally, we always include columns the user provided
+ * data for.
*/
- if (IsBootstrapProcessingMode())
+ aclresult = pg_class_aclcheck(reloid, GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
{
- elog(WARNING, "ExecReplace: replace can't run without transactions");
- return;
+ /* Set up the buffer for the column list */
+ initStringInfo(&collist);
+ appendStringInfoChar(&collist, '(');
}
+ else
+ table_perm = any_perm = true;
- /*
- * get the heap tuple out of the tuple table slot
- */
- tuple = slot->val;
-
- /*
- * get information on the (current) result relation
- */
- resultRelInfo = estate->es_result_relation_info;
- resultRelationDesc = resultRelInfo->ri_RelationDesc;
+ /* Make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
- /* BEFORE ROW UPDATE Triggers */
- if (resultRelInfo->ri_TrigDesc &&
- resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
+ for (i = 0; i < tupdesc->natts; i++)
{
- HeapTuple newtuple;
+ bool column_perm = false;
+ char *val;
+ int vallen;
- newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
- tupleid, tuple);
-
- if (newtuple == NULL) /* "do nothing" */
- return;
+ /* ignore dropped columns */
+ if (tupdesc->attrs[i]->attisdropped)
+ continue;
- if (newtuple != tuple) /* modified by Trigger(s) */
+ if (!table_perm)
{
/*
- * Insert modified tuple into tuple table slot, replacing the
- * original. We assume that it was allocated in per-tuple
- * memory context, and therefore will go away by itself. The
- * tuple table slot should not try to clear it.
+ * No table-level SELECT, so need to make sure they either have
+ * SELECT rights on the column or that they have provided the data
+ * for the column. If not, omit this column from the error
+ * message.
*/
- ExecStoreTuple(newtuple, slot, InvalidBuffer, false);
- tuple = newtuple;
- }
- }
-
- /*
- * Check the constraints of the tuple
- *
- * If we generate a new candidate tuple after EvalPlanQual testing, we
- * must loop back here and recheck constraints. (We don't need to
- * redo triggers, however. If there are any BEFORE triggers then
- * trigger.c will have done mark4update to lock the correct tuple, so
- * there's no need to do them again.)
- */
-lreplace:;
- if (resultRelationDesc->rd_att->constr)
- ExecConstraints("ExecReplace", resultRelInfo, slot, estate);
+ aclresult = pg_attribute_aclcheck(reloid, tupdesc->attrs[i]->attnum,
+ GetUserId(), ACL_SELECT);
+ if (bms_is_member(tupdesc->attrs[i]->attnum - FirstLowInvalidHeapAttributeNumber,
+ modifiedCols) || aclresult == ACLCHECK_OK)
+ {
+ column_perm = any_perm = true;
- /*
- * replace the heap tuple
- */
- result = heap_update(resultRelationDesc, tupleid, tuple,
- &ctid,
- estate->es_snapshot->curcid);
- switch (result)
- {
- case HeapTupleSelfUpdated:
- return;
+ if (write_comma_collist)
+ appendStringInfoString(&collist, ", ");
+ else
+ write_comma_collist = true;
- case HeapTupleMayBeUpdated:
- break;
+ appendStringInfoString(&collist, NameStr(tupdesc->attrs[i]->attname));
+ }
+ }
- case HeapTupleUpdated:
- if (XactIsoLevel == XACT_SERIALIZABLE)
- elog(ERROR, "Can't serialize access due to concurrent update");
- else if (!(ItemPointerEquals(tupleid, &ctid)))
+ if (table_perm || column_perm)
+ {
+ if (slot->tts_isnull[i])
+ val = "null";
+ else
{
- TupleTableSlot *epqslot = EvalPlanQual(estate,
- resultRelInfo->ri_RangeTableIndex, &ctid);
+ Oid foutoid;
+ bool typisvarlena;
- if (!TupIsNull(epqslot))
- {
- *tupleid = ctid;
- tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
- slot = ExecStoreTuple(tuple,
- estate->es_junkFilter->jf_resultSlot,
- InvalidBuffer, true);
- goto lreplace;
- }
+ getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
+ &foutoid, &typisvarlena);
+ val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
}
- /* tuple already deleted; nothing to do */
- return;
- default:
- elog(ERROR, "Unknown status %u from heap_update", result);
- return;
+ if (write_comma)
+ appendStringInfoString(&buf, ", ");
+ else
+ write_comma = true;
+
+ /* truncate if needed */
+ vallen = strlen(val);
+ if (vallen <= maxfieldlen)
+ appendStringInfoString(&buf, val);
+ else
+ {
+ vallen = pg_mbcliplen(val, vallen, maxfieldlen);
+ appendBinaryStringInfo(&buf, val, vallen);
+ appendStringInfoString(&buf, "...");
+ }
+ }
}
- IncrReplaced();
- (estate->es_processed)++;
+ /* If we end up with zero columns being returned, then return NULL. */
+ if (!any_perm)
+ return NULL;
- /*
- * 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 automagically by the vacuum daemon. All we
- * do is insert new index tuples. -cim 9/27/89
- */
+ appendStringInfoChar(&buf, ')');
- /*
- * process indices
- *
- * heap_update updates a tuple in the base relation by invalidating it
- * and then inserting a new tuple to the relation. As a side effect,
- * the tupleid of the new tuple is placed in the new tuple's t_ctid
- * field. So we now insert index tuples using the new tupleid stored
- * there.
- */
+ if (!table_perm)
+ {
+ appendStringInfoString(&collist, ") = ");
+ appendStringInfoString(&collist, buf.data);
- numIndices = resultRelInfo->ri_NumIndices;
- if (numIndices > 0)
- ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
+ return collist.data;
+ }
- /* AFTER ROW UPDATE Triggers */
- if (resultRelInfo->ri_TrigDesc)
- ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
+ return buf.data;
}
-static char *
-ExecRelCheck(ResultRelInfo *resultRelInfo,
- TupleTableSlot *slot, EState *estate)
+
+/*
+ * ExecUpdateLockMode -- find the appropriate UPDATE tuple lock mode for a
+ * given ResultRelInfo
+ */
+LockTupleMode
+ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo)
{
- 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;
+ Bitmapset *keyCols;
+ Bitmapset *updatedCols;
/*
- * 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.
+ * Compute lock mode to use. If columns that are part of the key have not
+ * been modified, then we can use a weaker lock, allowing for better
+ * concurrency.
*/
- if (resultRelInfo->ri_ConstraintExprs == NULL)
- {
- oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
- resultRelInfo->ri_ConstraintExprs =
- (List **) palloc(ncheck * sizeof(List *));
- for (i = 0; i < ncheck; i++)
- {
- qual = (List *) stringToNode(check[i].ccbin);
- resultRelInfo->ri_ConstraintExprs[i] = qual;
- }
- MemoryContextSwitchTo(oldContext);
- }
+ updatedCols = GetUpdatedColumns(relinfo, estate);
+ keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc,
+ INDEX_ATTR_BITMAP_KEY);
- /*
- * We will use the EState's per-tuple context for evaluating
- * constraint expressions (creating it if it's not already there).
- */
- econtext = GetPerTupleExprContext(estate);
+ if (bms_overlap(keyCols, updatedCols))
+ return LockTupleExclusive;
- /* Arrange for econtext's scan tuple to be the tuple under test */
- econtext->ecxt_scantuple = slot;
+ return LockTupleNoKeyExclusive;
+}
- /* And evaluate the constraints */
- for (i = 0; i < ncheck; i++)
+/*
+ * ExecFindRowMark -- find the ExecRowMark struct for given rangetable index
+ *
+ * If no such struct, either return NULL or throw error depending on missing_ok
+ */
+ExecRowMark *
+ExecFindRowMark(EState *estate, Index rti, bool missing_ok)
+{
+ ListCell *lc;
+
+ foreach(lc, estate->es_rowMarks)
{
- qual = resultRelInfo->ri_ConstraintExprs[i];
+ ExecRowMark *erm = (ExecRowMark *) lfirst(lc);
- /*
- * 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;
+ if (erm->rti == rti)
+ return erm;
}
-
- /* NULL result means no error */
- return (char *) NULL;
+ if (!missing_ok)
+ elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
+ return NULL;
}
-void
-ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo,
- TupleTableSlot *slot, EState *estate)
+/*
+ * ExecBuildAuxRowMark -- create an ExecAuxRowMark struct
+ *
+ * Inputs are the underlying ExecRowMark struct and the targetlist of the
+ * input plan node (not planstate node!). We need the latter to find out
+ * the column numbers of the resjunk columns.
+ */
+ExecAuxRowMark *
+ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
{
- Relation rel = resultRelInfo->ri_RelationDesc;
- HeapTuple tuple = slot->val;
- TupleConstr *constr = rel->rd_att->constr;
+ ExecAuxRowMark *aerm = (ExecAuxRowMark *) palloc0(sizeof(ExecAuxRowMark));
+ char resname[32];
- Assert(constr);
+ aerm->rowmark = erm;
- if (constr->has_not_null)
+ /* Look up the resjunk columns associated with this rowmark */
+ if (erm->markType != ROW_MARK_COPY)
{
- int natts = rel->rd_att->natts;
- int attrChk;
-
- for (attrChk = 1; attrChk <= natts; attrChk++)
- {
- if (rel->rd_att->attrs[attrChk - 1]->attnotnull &&
- heap_attisnull(tuple, attrChk))
- elog(ERROR, "%s: Fail to add null value in not null attribute %s",
- caller, NameStr(rel->rd_att->attrs[attrChk - 1]->attname));
- }
+ /* need ctid for all methods other than COPY */
+ snprintf(resname, sizeof(resname), "ctid%u", erm->rowmarkId);
+ aerm->ctidAttNo = ExecFindJunkAttributeInTlist(targetlist,
+ resname);
+ if (!AttributeNumberIsValid(aerm->ctidAttNo))
+ elog(ERROR, "could not find junk %s column", resname);
}
-
- if (constr->num_check > 0)
+ else
{
- char *failed;
+ /* need wholerow if COPY */
+ snprintf(resname, sizeof(resname), "wholerow%u", erm->rowmarkId);
+ aerm->wholeAttNo = ExecFindJunkAttributeInTlist(targetlist,
+ resname);
+ if (!AttributeNumberIsValid(aerm->wholeAttNo))
+ elog(ERROR, "could not find junk %s column", resname);
+ }
- if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
- elog(ERROR, "%s: rejected due to CHECK constraint %s",
- caller, failed);
+ /* if child rel, need tableoid */
+ if (erm->rti != erm->prti)
+ {
+ snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
+ aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
+ resname);
+ if (!AttributeNumberIsValid(aerm->toidAttNo))
+ elog(ERROR, "could not find junk %s column", resname);
}
+
+ return aerm;
}
+
+/*
+ * 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.
*
- * See backend/executor/README for some info about how this works.
+ * estate - outer executor state data
+ * epqstate - state for EvalPlanQual rechecking
+ * relation - table containing tuple
+ * rti - rangetable index of 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
+ *
+ * *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.
+ *
+ * Note: properly, lockmode should be declared as enum LockTupleMode,
+ * but we use "int" to avoid having to include heapam.h in executor.h.
*/
TupleTableSlot *
-EvalPlanQual(EState *estate, Index rti, ItemPointer tid)
+EvalPlanQual(EState *estate, EPQState *epqstate,
+ Relation relation, Index rti, int lockmode,
+ ItemPointer tid, TransactionId priorXmax)
{
- evalPlanQual *epq;
- EState *epqstate;
- Relation relation;
- HeapTupleData tuple;
- HeapTuple copyTuple = NULL;
- int rtsize;
- bool endNode;
+ TupleTableSlot *slot;
+ HeapTuple copyTuple;
- Assert(rti != 0);
+ Assert(rti > 0);
/*
- * find relation containing target tuple
+ * Get and lock the updated version of the row; if fail, return NULL.
*/
- if (estate->es_result_relation_info != NULL &&
- estate->es_result_relation_info->ri_RangeTableIndex == rti)
- relation = estate->es_result_relation_info->ri_RelationDesc;
- else
- {
- List *l;
+ copyTuple = EvalPlanQualFetch(estate, relation, lockmode, LockWaitBlock,
+ tid, priorXmax);
- relation = NULL;
- foreach(l, estate->es_rowMark)
- {
- if (((execRowMark *) lfirst(l))->rti == rti)
- {
- relation = ((execRowMark *) lfirst(l))->relation;
- break;
- }
- }
- if (relation == NULL)
- elog(ERROR, "EvalPlanQual: can't find RTE %d", (int) rti);
- }
+ 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
+ * wait_policy - requested lock wait policy
+ * *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).
+ * We also return NULL if the tuple is locked and the wait policy is to skip
+ * such tuples.
+ *
+ * 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,
+ LockWaitPolicy wait_policy,
+ ItemPointer tid, TransactionId priorXmax)
+{
+ HeapTuple copyTuple = NULL;
+ HeapTupleData tuple;
+ SnapshotData SnapshotDirty;
/*
- * fetch tid tuple
+ * 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, false, NULL))
+ if (heap_fetch(relation, &SnapshotDirty, &tuple, &buffer, true, NULL))
{
- TransactionId xwait = SnapshotDirty->xmax;
+ HTSU_Result test;
+ HeapUpdateFailureData hufd;
+
+ /*
+ * 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. We assume reading a TransactionId to be
+ * atomic, and Xmin never changes in an existing tuple, except to
+ * invalid or frozen, and neither of those can match priorXmax.)
+ */
+ if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
+ priorXmax))
+ {
+ ReleaseBuffer(buffer);
+ return NULL;
+ }
- if (TransactionIdIsValid(SnapshotDirty->xmin))
- elog(ERROR, "EvalPlanQual: t_xmin is uncommitted ?!");
+ /* 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 tuple is being updated by other transaction then we have to
+ * wait for its commit/abort, or die trying.
*/
- if (TransactionIdIsValid(xwait))
+ if (TransactionIdIsValid(SnapshotDirty.xmax))
{
ReleaseBuffer(buffer);
- XactLockTableWait(xwait);
- continue;
+ switch (wait_policy)
+ {
+ case LockWaitBlock:
+ XactLockTableWait(SnapshotDirty.xmax,
+ relation, &tuple.t_self,
+ XLTW_FetchUpdated);
+ break;
+ case LockWaitSkip:
+ if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
+ return NULL; /* skip instead of waiting */
+ break;
+ case LockWaitError:
+ if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
+ ereport(ERROR,
+ (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+ errmsg("could not obtain lock on row in relation \"%s\"",
+ RelationGetRelationName(relation))));
+ break;
+ }
+ 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. Otherwise
+ * heap_lock_tuple() will throw an error, and so would any later
+ * attempt to update or delete the 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,
+ estate->es_output_cid,
+ lockmode, wait_policy,
+ false, &buffer, &hufd);
+ /* We now have two pins on the buffer, get rid of one */
+ ReleaseBuffer(buffer);
+
+ switch (test)
+ {
+ case HeapTupleSelfUpdated:
+
+ /*
+ * The target tuple was already updated or deleted by the
+ * current command, or by a later command in the current
+ * transaction. We *must* ignore the tuple in the former
+ * case, so as to avoid the "Halloween problem" of
+ * repeated update attempts. In the latter case it might
+ * be sensible to fetch the updated tuple instead, but
+ * doing so would require changing heap_update and
+ * heap_delete to not complain about updating "invisible"
+ * tuples, which seems pretty scary (heap_lock_tuple will
+ * not complain, but few callers expect
+ * HeapTupleInvisible, and we're not one of them). So for
+ * now, treat the tuple as deleted and do not process.
+ */
+ ReleaseBuffer(buffer);
+ return NULL;
+
+ case HeapTupleMayBeUpdated:
+ /* successfully locked */
+ break;
+
+ case HeapTupleUpdated:
+ ReleaseBuffer(buffer);
+ if (IsolationUsesXactSnapshot())
+ ereport(ERROR,
+ (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+ errmsg("could not serialize access due to concurrent update")));
+
+ /* Should not encounter speculative tuple on recheck */
+ Assert(!HeapTupleHeaderIsSpeculative(tuple.t_data));
+ if (!ItemPointerEquals(&hufd.ctid, &tuple.t_self))
+ {
+ /* it was updated, so look at the updated version */
+ tuple.t_self = hufd.ctid;
+ /* updated row should have xmin matching this xmax */
+ priorXmax = hufd.xmax;
+ continue;
+ }
+ /* tuple was deleted, so give up */
+ return NULL;
+
+ case HeapTupleWouldBlock:
+ ReleaseBuffer(buffer);
+ return NULL;
+
+ case HeapTupleInvisible:
+ elog(ERROR, "attempted to lock invisible tuple");
+
+ default:
+ ReleaseBuffer(buffer);
+ elog(ERROR, "unrecognized heap_lock_tuple status: %u",
+ test);
+ return NULL; /* keep compiler quiet */
}
/*
}
/*
- * Oops! Invalid tuple. Have to check is it updated or deleted.
- * Note that it's possible to get invalid SnapshotDirty->tid if
- * tuple updated by this transaction. Have we to check this ?
+ * If the referenced slot was actually empty, the latest version of
+ * the row must have been deleted, so we need do nothing.
*/
- if (ItemPointerIsValid(&(SnapshotDirty->tid)) &&
- !(ItemPointerEquals(&(tuple.t_self), &(SnapshotDirty->tid))))
+ if (tuple.t_data == NULL)
{
- /* updated, so look at the updated copy */
- tuple.t_self = SnapshotDirty->tid;
- continue;
+ ReleaseBuffer(buffer);
+ return NULL;
}
/*
- * Deleted or updated by this transaction; forget it.
+ * As above, if xmin isn't what we're expecting, do nothing.
*/
- return NULL;
+ 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 = HeapTupleHeaderGetUpdateXid(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.
+ * Return the copied tuple
*/
- *tid = tuple.t_self;
+ return copyTuple;
+}
- /*
- * Need to run a recheck subquery. Find or create a PQ stack entry.
- */
- epq = (evalPlanQual *) estate->es_evalPlanQual;
- rtsize = length(estate->es_range_table);
- endNode = true;
+/*
+ * EvalPlanQualInit -- initialize during creation of a plan state node
+ * that might need to invoke EPQ processing.
+ *
+ * Note: subplan/auxrowmarks can be NULL/NIL if they will be set later
+ * with EvalPlanQualSetPlan.
+ */
+void
+EvalPlanQualInit(EPQState *epqstate, EState *estate,
+ Plan *subplan, List *auxrowmarks, 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->arowMarks = auxrowmarks;
+ epqstate->epqParam = epqParam;
+}
- if (epq != NULL && epq->rti == 0)
- {
- /* Top PQ stack entry is idle, so re-use it */
- Assert(!(estate->es_useEvalPlan) &&
- epq->estate.es_evalPlanQual == NULL);
- epq->rti = rti;
- endNode = false;
- }
+/*
+ * EvalPlanQualSetPlan -- set or change subplan of an EPQState.
+ *
+ * We need this so that ModifyTable can deal with multiple subplans.
+ */
+void
+EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan, List *auxrowmarks)
+{
+ /* If we have a live EPQ query, shut it down */
+ EvalPlanQualEnd(epqstate);
+ /* And set/change the plan pointer */
+ epqstate->plan = subplan;
+ /* The rowmarks depend on the plan, too */
+ epqstate->arowMarks = auxrowmarks;
+}
+
+/*
+ * 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);
/*
- * 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? -:))
+ * free old test tuple, if any, and store new tuple where relation's scan
+ * node will see it
*/
- if (epq != NULL && epq->rti != rti &&
- epq->estate.es_evTuple[rti - 1] != NULL)
+ 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->arowMarks)
{
- do
+ ExecAuxRowMark *aerm = (ExecAuxRowMark *) lfirst(l);
+ ExecRowMark *erm = aerm->rowmark;
+ Datum datum;
+ bool isNull;
+ HeapTupleData tuple;
+
+ if (RowMarkRequiresRowShareLock(erm->markType))
+ elog(ERROR, "EvalPlanQual doesn't support locking rowmarks");
+
+ /* clear any leftover test tuple for this rel */
+ EvalPlanQualSetTuple(epqstate, erm->rti, NULL);
+
+ /* if child rel, must check whether it produced this row */
+ if (erm->rti != erm->prti)
{
- evalPlanQual *oldepq;
-
- /* pop previous PlanQual from the stack */
- epqstate = &(epq->estate);
- oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
- Assert(oldepq->rti != 0);
- /* stop execution */
- ExecEndNode(epq->plan, NULL);
- ExecDropTupleTable(epqstate->es_tupleTable, true);
- epqstate->es_tupleTable = NULL;
- heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
- epqstate->es_evTuple[epq->rti - 1] = NULL;
- /* push current PQ to freePQ stack */
- oldepq->free = epq;
- epq = oldepq;
- estate->es_evalPlanQual = (Pointer) epq;
- } while (epq->rti != rti);
- }
+ Oid tableoid;
- /*
- * 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;
+ datum = ExecGetJunkAttribute(epqstate->origslot,
+ aerm->toidAttNo,
+ &isNull);
+ /* non-locked rels could be on the inside of outer joins */
+ if (isNull)
+ continue;
+ tableoid = DatumGetObjectId(datum);
+
+ Assert(OidIsValid(erm->relid));
+ if (tableoid != erm->relid)
+ {
+ /* this child is inactive right now */
+ continue;
+ }
+ }
- if (newepq == NULL) /* first call or freePQ stack is empty */
+ if (erm->markType == ROW_MARK_REFERENCE)
{
- newepq = (evalPlanQual *) palloc(sizeof(evalPlanQual));
- newepq->free = NULL;
+ HeapTuple copyTuple;
- /*
- * Each stack level has its own copy of the plan tree. This
- * is wasteful, but necessary as long as plan nodes point to
- * exec state nodes rather than vice versa. Note that
- * copyfuncs.c doesn't attempt to copy the exec state nodes,
- * which is a good thing in this situation.
- */
- newepq->plan = copyObject(estate->es_origPlan);
+ Assert(erm->relation != NULL);
- /*
- * Init stack level's EState. We share top level's copy of
- * es_result_relations array and other non-changing status. We
- * need our own tupletable, es_param_exec_vals, and other
- * changeable state.
- */
- epqstate = &(newepq->estate);
- memcpy(epqstate, estate, sizeof(EState));
- epqstate->es_direction = ForwardScanDirection;
- if (estate->es_origPlan->nParamExec > 0)
- epqstate->es_param_exec_vals = (ParamExecData *)
- palloc(estate->es_origPlan->nParamExec *
- sizeof(ParamExecData));
- epqstate->es_tupleTable = NULL;
- epqstate->es_per_tuple_exprcontext = NULL;
+ /* fetch the tuple's ctid */
+ datum = ExecGetJunkAttribute(epqstate->origslot,
+ aerm->ctidAttNo,
+ &isNull);
+ /* non-locked rels could be on the inside of outer joins */
+ if (isNull)
+ continue;
- /*
- * Each epqstate must have its own es_evTupleNull state, but
- * all the stack entries share es_evTuple state. This allows
- * sub-rechecks to inherit the value being examined by an
- * outer recheck.
- */
- epqstate->es_evTupleNull = (bool *) palloc(rtsize * sizeof(bool));
- if (epq == NULL)
+ /* fetch requests on foreign tables must be passed to their FDW */
+ if (erm->relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
{
- /* first PQ stack entry */
- epqstate->es_evTuple = (HeapTuple *)
- palloc(rtsize * sizeof(HeapTuple));
- memset(epqstate->es_evTuple, 0, rtsize * sizeof(HeapTuple));
+ FdwRoutine *fdwroutine;
+ bool updated = false;
+
+ fdwroutine = GetFdwRoutineForRelation(erm->relation, false);
+ /* this should have been checked already, but let's be safe */
+ if (fdwroutine->RefetchForeignRow == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot lock rows in foreign table \"%s\"",
+ RelationGetRelationName(erm->relation))));
+ copyTuple = fdwroutine->RefetchForeignRow(epqstate->estate,
+ erm,
+ datum,
+ &updated);
+ if (copyTuple == NULL)
+ elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+
+ /*
+ * Ideally we'd insist on updated == false here, but that
+ * assumes that FDWs can track that exactly, which they might
+ * not be able to. So just ignore the flag.
+ */
}
else
{
- /* later stack entries share the same storage */
- epqstate->es_evTuple = epq->estate.es_evTuple;
+ /* ordinary table, fetch the tuple */
+ Buffer buffer;
+
+ tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
+ if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
+ false, NULL))
+ elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+
+ /* successful, copy tuple */
+ copyTuple = heap_copytuple(&tuple);
+ ReleaseBuffer(buffer);
}
+
+ /* store tuple */
+ EvalPlanQualSetTuple(epqstate, erm->rti, copyTuple);
}
else
{
- /* recycle previously used EState */
- epqstate = &(newepq->estate);
+ HeapTupleHeader td;
+
+ Assert(erm->markType == ROW_MARK_COPY);
+
+ /* fetch the whole-row Var for the relation */
+ datum = ExecGetJunkAttribute(epqstate->origslot,
+ aerm->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);
+ tuple.t_data = td;
+ /* relation might be a foreign table, if so provide tableoid */
+ tuple.t_tableOid = erm->relid;
+ /* also copy t_ctid in case there's valid data there */
+ tuple.t_self = td->t_ctid;
+
+ /* copy and store tuple */
+ EvalPlanQualSetTuple(epqstate, erm->rti,
+ heap_copytuple(&tuple));
}
- /* push current PQ to the stack */
- epqstate->es_evalPlanQual = (Pointer) epq;
- epq = newepq;
- estate->es_evalPlanQual = (Pointer) epq;
- epq->rti = rti;
- endNode = false;
}
+}
+
+/*
+ * 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;
- Assert(epq->rti == rti);
- epqstate = &(epq->estate);
+ oldcontext = MemoryContextSwitchTo(epqstate->estate->es_query_cxt);
+ slot = ExecProcNode(epqstate->planstate);
+ MemoryContextSwitchTo(oldcontext);
- /*
- * Ok - we're requested for the same RTE. Unfortunately we still have
- * to end and restart execution of the plan, because ExecReScan
- * wouldn't ensure that upper plan nodes would reset themselves. We
- * could make that work if insertion of the target tuple were
- * integrated with the Param mechanism somehow, so that the upper plan
- * nodes know that their children's outputs have changed.
- */
- if (endNode)
+ return slot;
+}
+
+/*
+ * Initialize or reset an EvalPlanQual state tree
+ */
+void
+EvalPlanQualBegin(EPQState *epqstate, EState *parentestate)
+{
+ EState *estate = epqstate->estate;
+
+ if (estate == NULL)
{
- /* stop execution */
- ExecEndNode(epq->plan, NULL);
- ExecDropTupleTable(epqstate->es_tupleTable, true);
- epqstate->es_tupleTable = 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;
- /*
- * free old RTE' tuple, if any, and store target tuple where
- * relation's scan node will see it
- */
- if (epqstate->es_evTuple[rti - 1] != NULL)
- heap_freetuple(epqstate->es_evTuple[rti - 1]);
- epqstate->es_evTuple[rti - 1] = copyTuple;
+ MemSet(estate->es_epqScanDone, 0, rtsize * sizeof(bool));
- /*
- * Initialize for new recheck query; be careful to copy down state
- * that might have changed in top EState.
- */
- epqstate->es_result_relation_info = estate->es_result_relation_info;
- epqstate->es_junkFilter = estate->es_junkFilter;
- if (estate->es_origPlan->nParamExec > 0)
- memset(epqstate->es_param_exec_vals, 0,
- estate->es_origPlan->nParamExec * sizeof(ParamExecData));
- memset(epqstate->es_evTupleNull, false, rtsize * sizeof(bool));
- epqstate->es_useEvalPlan = false;
- Assert(epqstate->es_tupleTable == NULL);
- epqstate->es_tupleTable =
- ExecCreateTupleTable(estate->es_tupleTable->size);
+ /* Recopy current values of parent parameters */
+ if (parentestate->es_plannedstmt->nParamExec > 0)
+ {
+ int i = parentestate->es_plannedstmt->nParamExec;
- ExecInitNode(epq->plan, epqstate, NULL);
+ 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;
+ }
+ }
- return EvalPlanQualNext(estate);
+ /*
+ * 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);
+ }
}
-static TupleTableSlot *
-EvalPlanQualNext(EState *estate)
+/*
+ * 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)
{
- evalPlanQual *epq = (evalPlanQual *) estate->es_evalPlanQual;
- EState *epqstate = &(epq->estate);
- evalPlanQual *oldepq;
- TupleTableSlot *slot;
+ 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);
- Assert(epq->rti != 0);
+ /*
+ * 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.
+ *
+ * The ResultRelInfo array management is trickier than it looks. We
+ * create a fresh array for the child but copy all the content from the
+ * parent. This is because it's okay for the child to share any
+ * per-relation state the parent has already created --- but if the child
+ * sets up any ResultRelInfo fields, such as its own junkfilter, that
+ * state must *not* propagate back to the parent. (For one thing, the
+ * pointed-to data is in a memory context that won't last long enough.)
+ */
+ 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;
+ if (parentestate->es_num_result_relations > 0)
+ {
+ int numResultRelations = parentestate->es_num_result_relations;
+ ResultRelInfo *resultRelInfos;
-lpqnext:;
- slot = ExecProcNode(epq->plan, NULL);
+ resultRelInfos = (ResultRelInfo *)
+ palloc(numResultRelations * sizeof(ResultRelInfo));
+ memcpy(resultRelInfos, parentestate->es_result_relations,
+ numResultRelations * sizeof(ResultRelInfo));
+ estate->es_result_relations = resultRelInfos;
+ estate->es_num_result_relations = numResultRelations;
+ }
+ /* es_result_relation_info must NOT be copied */
+ /* es_trig_target_relations must NOT be copied */
+ estate->es_rowMarks = parentestate->es_rowMarks;
+ estate->es_top_eflags = parentestate->es_top_eflags;
+ estate->es_instrument = parentestate->es_instrument;
+ /* es_auxmodifytables must NOT be copied */
/*
- * No more tuples for this PQ. Continue previous one.
+ * 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.
*/
- if (TupIsNull(slot))
+ estate->es_param_list_info = parentestate->es_param_list_info;
+ if (parentestate->es_plannedstmt->nParamExec > 0)
{
- /* stop execution */
- ExecEndNode(epq->plan, NULL);
- ExecDropTupleTable(epqstate->es_tupleTable, true);
- epqstate->es_tupleTable = NULL;
- heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
- epqstate->es_evTuple[epq->rti - 1] = NULL;
- /* pop old PQ from the stack */
- oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
- if (oldepq == (evalPlanQual *) NULL)
+ int i = parentestate->es_plannedstmt->nParamExec;
+
+ estate->es_param_exec_vals = (ParamExecData *)
+ palloc0(i * sizeof(ParamExecData));
+ while (--i >= 0)
{
- epq->rti = 0; /* this is the first (oldest) */
- estate->es_useEvalPlan = false; /* PQ - mark as free and */
- return (NULL); /* continue Query execution */
+ /* 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;
}
- Assert(oldepq->rti != 0);
- /* push current PQ to freePQ stack */
- oldepq->free = epq;
- epq = oldepq;
- epqstate = &(epq->estate);
- estate->es_evalPlanQual = (Pointer) epq;
- goto lpqnext;
}
- return (slot);
+ /*
+ * 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);
}
-static void
-EndEvalPlanQual(EState *estate)
+/*
+ * 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)
{
- evalPlanQual *epq = (evalPlanQual *) estate->es_evalPlanQual;
- EState *epqstate = &(epq->estate);
- evalPlanQual *oldepq;
+ 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);
- if (epq->rti == 0) /* plans already shutdowned */
+ foreach(l, estate->es_subplanstates)
{
- Assert(epq->estate.es_evalPlanQual == NULL);
- return;
+ PlanState *subplanstate = (PlanState *) lfirst(l);
+
+ ExecEndNode(subplanstate);
}
- for (;;)
+ /* 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)
{
- /* stop execution */
- ExecEndNode(epq->plan, NULL);
- ExecDropTupleTable(epqstate->es_tupleTable, true);
- epqstate->es_tupleTable = NULL;
- if (epqstate->es_evTuple[epq->rti - 1] != NULL)
- {
- heap_freetuple(epqstate->es_evTuple[epq->rti - 1]);
- epqstate->es_evTuple[epq->rti - 1] = NULL;
- }
- /* pop old PQ from the stack */
- oldepq = (evalPlanQual *) epqstate->es_evalPlanQual;
- if (oldepq == (evalPlanQual *) NULL)
- {
- epq->rti = 0; /* this is the first (oldest) */
- estate->es_useEvalPlan = false; /* PQ - mark as free */
- break;
- }
- Assert(oldepq->rti != 0);
- /* push current PQ to freePQ stack */
- oldepq->free = epq;
- epq = oldepq;
- epqstate = &(epq->estate);
- estate->es_evalPlanQual = (Pointer) epq;
+ 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;
}
projects / postgresql / blobdiff