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000128bc7f
We need ExecutorEnd to run the ModifyTable nodes to completion in reverse order of initialization, not forward order. Easily done by constructing the list back-to-front.
1206 lines
34 KiB
C
1206 lines
34 KiB
C
/*-------------------------------------------------------------------------
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*
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* nodeModifyTable.c
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* routines to handle ModifyTable nodes.
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*
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* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/executor/nodeModifyTable.c
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*
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*-------------------------------------------------------------------------
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*/
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/* INTERFACE ROUTINES
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* ExecInitModifyTable - initialize the ModifyTable node
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* ExecModifyTable - retrieve the next tuple from the node
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* ExecEndModifyTable - shut down the ModifyTable node
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* ExecReScanModifyTable - rescan the ModifyTable node
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*
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* NOTES
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* Each ModifyTable node contains a list of one or more subplans,
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* much like an Append node. There is one subplan per result relation.
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* The key reason for this is that in an inherited UPDATE command, each
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* result relation could have a different schema (more or different
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* columns) requiring a different plan tree to produce it. In an
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* inherited DELETE, all the subplans should produce the same output
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* rowtype, but we might still find that different plans are appropriate
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* for different child relations.
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*
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* If the query specifies RETURNING, then the ModifyTable returns a
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* RETURNING tuple after completing each row insert, update, or delete.
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* It must be called again to continue the operation. Without RETURNING,
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* we just loop within the node until all the work is done, then
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* return NULL. This avoids useless call/return overhead.
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*/
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#include "postgres.h"
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#include "access/xact.h"
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#include "commands/trigger.h"
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#include "executor/executor.h"
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#include "executor/nodeModifyTable.h"
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#include "miscadmin.h"
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#include "nodes/nodeFuncs.h"
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#include "storage/bufmgr.h"
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#include "utils/builtins.h"
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#include "utils/memutils.h"
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#include "utils/tqual.h"
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/*
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* Verify that the tuples to be produced by INSERT or UPDATE match the
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* target relation's rowtype
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*
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* We do this to guard against stale plans. If plan invalidation is
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* functioning properly then we should never get a failure here, but better
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* safe than sorry. Note that this is called after we have obtained lock
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* on the target rel, so the rowtype can't change underneath us.
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*
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* The plan output is represented by its targetlist, because that makes
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* handling the dropped-column case easier.
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*/
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static void
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ExecCheckPlanOutput(Relation resultRel, List *targetList)
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{
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TupleDesc resultDesc = RelationGetDescr(resultRel);
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int attno = 0;
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ListCell *lc;
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foreach(lc, targetList)
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{
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TargetEntry *tle = (TargetEntry *) lfirst(lc);
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Form_pg_attribute attr;
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if (tle->resjunk)
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continue; /* ignore junk tlist items */
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if (attno >= resultDesc->natts)
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ereport(ERROR,
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(errcode(ERRCODE_DATATYPE_MISMATCH),
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errmsg("table row type and query-specified row type do not match"),
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errdetail("Query has too many columns.")));
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attr = resultDesc->attrs[attno++];
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if (!attr->attisdropped)
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{
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/* Normal case: demand type match */
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if (exprType((Node *) tle->expr) != attr->atttypid)
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ereport(ERROR,
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(errcode(ERRCODE_DATATYPE_MISMATCH),
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errmsg("table row type and query-specified row type do not match"),
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errdetail("Table has type %s at ordinal position %d, but query expects %s.",
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format_type_be(attr->atttypid),
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attno,
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format_type_be(exprType((Node *) tle->expr)))));
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}
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else
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{
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/*
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* For a dropped column, we can't check atttypid (it's likely 0).
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* In any case the planner has most likely inserted an INT4 null.
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* What we insist on is just *some* NULL constant.
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*/
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if (!IsA(tle->expr, Const) ||
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!((Const *) tle->expr)->constisnull)
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ereport(ERROR,
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(errcode(ERRCODE_DATATYPE_MISMATCH),
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errmsg("table row type and query-specified row type do not match"),
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errdetail("Query provides a value for a dropped column at ordinal position %d.",
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attno)));
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}
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}
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if (attno != resultDesc->natts)
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ereport(ERROR,
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(errcode(ERRCODE_DATATYPE_MISMATCH),
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errmsg("table row type and query-specified row type do not match"),
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errdetail("Query has too few columns.")));
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}
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/*
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* ExecProcessReturning --- evaluate a RETURNING list
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*
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* projectReturning: RETURNING projection info for current result rel
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* tupleSlot: slot holding tuple actually inserted/updated/deleted
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* planSlot: slot holding tuple returned by top subplan node
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*
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* Returns a slot holding the result tuple
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*/
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static TupleTableSlot *
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ExecProcessReturning(ProjectionInfo *projectReturning,
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TupleTableSlot *tupleSlot,
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TupleTableSlot *planSlot)
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{
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ExprContext *econtext = projectReturning->pi_exprContext;
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/*
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* Reset per-tuple memory context to free any expression evaluation
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* storage allocated in the previous cycle.
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*/
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ResetExprContext(econtext);
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/* Make tuple and any needed join variables available to ExecProject */
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econtext->ecxt_scantuple = tupleSlot;
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econtext->ecxt_outertuple = planSlot;
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/* Compute the RETURNING expressions */
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return ExecProject(projectReturning, NULL);
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}
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/* ----------------------------------------------------------------
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* ExecInsert
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*
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* For INSERT, we have to insert the tuple into the target relation
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* and insert appropriate tuples into the index relations.
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*
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* Returns RETURNING result if any, otherwise NULL.
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* ----------------------------------------------------------------
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*/
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static TupleTableSlot *
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ExecInsert(TupleTableSlot *slot,
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TupleTableSlot *planSlot,
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EState *estate,
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bool canSetTag)
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{
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HeapTuple tuple;
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ResultRelInfo *resultRelInfo;
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Relation resultRelationDesc;
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Oid newId;
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List *recheckIndexes = NIL;
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/*
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* get the heap tuple out of the tuple table slot, making sure we have a
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* writable copy
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*/
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tuple = ExecMaterializeSlot(slot);
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/*
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* get information on the (current) result relation
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*/
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resultRelInfo = estate->es_result_relation_info;
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resultRelationDesc = resultRelInfo->ri_RelationDesc;
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/*
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* If the result relation has OIDs, force the tuple's OID to zero so that
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* heap_insert will assign a fresh OID. Usually the OID already will be
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* zero at this point, but there are corner cases where the plan tree can
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* return a tuple extracted literally from some table with the same
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* rowtype.
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*
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* XXX if we ever wanted to allow users to assign their own OIDs to new
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* rows, this'd be the place to do it. For the moment, we make a point of
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* doing this before calling triggers, so that a user-supplied trigger
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* could hack the OID if desired.
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*/
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if (resultRelationDesc->rd_rel->relhasoids)
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HeapTupleSetOid(tuple, InvalidOid);
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/* BEFORE ROW INSERT Triggers */
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if (resultRelInfo->ri_TrigDesc &&
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resultRelInfo->ri_TrigDesc->trig_insert_before_row)
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{
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slot = ExecBRInsertTriggers(estate, resultRelInfo, slot);
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if (slot == NULL) /* "do nothing" */
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return NULL;
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/* trigger might have changed tuple */
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tuple = ExecMaterializeSlot(slot);
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}
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/* INSTEAD OF ROW INSERT Triggers */
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if (resultRelInfo->ri_TrigDesc &&
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resultRelInfo->ri_TrigDesc->trig_insert_instead_row)
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{
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slot = ExecIRInsertTriggers(estate, resultRelInfo, slot);
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if (slot == NULL) /* "do nothing" */
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return NULL;
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/* trigger might have changed tuple */
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tuple = ExecMaterializeSlot(slot);
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newId = InvalidOid;
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}
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else
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{
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/*
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* Check the constraints of the tuple
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*/
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if (resultRelationDesc->rd_att->constr)
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ExecConstraints(resultRelInfo, slot, estate);
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/*
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* insert the tuple
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*
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* Note: heap_insert returns the tid (location) of the new tuple in
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* the t_self field.
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*/
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newId = heap_insert(resultRelationDesc, tuple,
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estate->es_output_cid, 0, NULL);
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/*
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* insert index entries for tuple
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*/
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if (resultRelInfo->ri_NumIndices > 0)
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recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
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estate);
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}
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if (canSetTag)
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{
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(estate->es_processed)++;
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estate->es_lastoid = newId;
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setLastTid(&(tuple->t_self));
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}
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/* AFTER ROW INSERT Triggers */
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ExecARInsertTriggers(estate, resultRelInfo, tuple, recheckIndexes);
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list_free(recheckIndexes);
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/* Process RETURNING if present */
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if (resultRelInfo->ri_projectReturning)
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return ExecProcessReturning(resultRelInfo->ri_projectReturning,
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slot, planSlot);
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return NULL;
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}
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/* ----------------------------------------------------------------
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* ExecDelete
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*
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* DELETE is like UPDATE, except that we delete the tuple and no
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* index modifications are needed.
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*
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* When deleting from a table, tupleid identifies the tuple to
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* delete and oldtuple is NULL. When deleting from a view,
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* oldtuple is passed to the INSTEAD OF triggers and identifies
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* what to delete, and tupleid is invalid.
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*
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* Returns RETURNING result if any, otherwise NULL.
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* ----------------------------------------------------------------
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*/
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static TupleTableSlot *
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ExecDelete(ItemPointer tupleid,
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HeapTupleHeader oldtuple,
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TupleTableSlot *planSlot,
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EPQState *epqstate,
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EState *estate,
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bool canSetTag)
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{
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ResultRelInfo *resultRelInfo;
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Relation resultRelationDesc;
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HTSU_Result result;
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ItemPointerData update_ctid;
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TransactionId update_xmax;
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/*
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* get information on the (current) result relation
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*/
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resultRelInfo = estate->es_result_relation_info;
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resultRelationDesc = resultRelInfo->ri_RelationDesc;
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/* BEFORE ROW DELETE Triggers */
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if (resultRelInfo->ri_TrigDesc &&
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resultRelInfo->ri_TrigDesc->trig_delete_before_row)
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{
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bool dodelete;
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dodelete = ExecBRDeleteTriggers(estate, epqstate, resultRelInfo,
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tupleid);
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if (!dodelete) /* "do nothing" */
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return NULL;
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}
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/* INSTEAD OF ROW DELETE Triggers */
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if (resultRelInfo->ri_TrigDesc &&
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resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
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{
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HeapTupleData tuple;
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bool dodelete;
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Assert(oldtuple != NULL);
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tuple.t_data = oldtuple;
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tuple.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
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ItemPointerSetInvalid(&(tuple.t_self));
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tuple.t_tableOid = InvalidOid;
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dodelete = ExecIRDeleteTriggers(estate, resultRelInfo, &tuple);
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if (!dodelete) /* "do nothing" */
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return NULL;
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}
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else
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{
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/*
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* delete the tuple
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*
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* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check
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* that the row to be deleted is visible to that snapshot, and throw a
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* can't-serialize error if not. This is a special-case behavior
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* needed for referential integrity updates in transaction-snapshot
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* mode transactions.
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*/
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ldelete:;
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result = heap_delete(resultRelationDesc, tupleid,
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&update_ctid, &update_xmax,
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estate->es_output_cid,
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estate->es_crosscheck_snapshot,
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true /* wait for commit */ );
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switch (result)
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{
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case HeapTupleSelfUpdated:
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/* already deleted by self; nothing to do */
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return NULL;
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case HeapTupleMayBeUpdated:
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break;
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case HeapTupleUpdated:
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if (IsolationUsesXactSnapshot())
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ereport(ERROR,
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(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
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errmsg("could not serialize access due to concurrent update")));
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if (!ItemPointerEquals(tupleid, &update_ctid))
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{
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TupleTableSlot *epqslot;
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epqslot = EvalPlanQual(estate,
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epqstate,
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resultRelationDesc,
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resultRelInfo->ri_RangeTableIndex,
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&update_ctid,
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update_xmax);
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if (!TupIsNull(epqslot))
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{
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*tupleid = update_ctid;
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goto ldelete;
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}
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}
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/* tuple already deleted; nothing to do */
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return NULL;
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default:
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elog(ERROR, "unrecognized heap_delete status: %u", result);
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return NULL;
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}
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/*
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* Note: Normally one would think that we have to delete index tuples
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* associated with the heap tuple now...
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*
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* ... but in POSTGRES, we have no need to do this because VACUUM will
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* take care of it later. We can't delete index tuples immediately
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* anyway, since the tuple is still visible to other transactions.
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*/
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}
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if (canSetTag)
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(estate->es_processed)++;
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/* AFTER ROW DELETE Triggers */
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ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
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/* Process RETURNING if present */
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if (resultRelInfo->ri_projectReturning)
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{
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/*
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* We have to put the target tuple into a slot, which means first we
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* gotta fetch it. We can use the trigger tuple slot.
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*/
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TupleTableSlot *slot = estate->es_trig_tuple_slot;
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TupleTableSlot *rslot;
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HeapTupleData deltuple;
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Buffer delbuffer;
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if (oldtuple != NULL)
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{
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deltuple.t_data = oldtuple;
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deltuple.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
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ItemPointerSetInvalid(&(deltuple.t_self));
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deltuple.t_tableOid = InvalidOid;
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delbuffer = InvalidBuffer;
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}
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else
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{
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deltuple.t_self = *tupleid;
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if (!heap_fetch(resultRelationDesc, SnapshotAny,
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&deltuple, &delbuffer, false, NULL))
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elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
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}
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if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
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ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
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ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
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rslot = ExecProcessReturning(resultRelInfo->ri_projectReturning,
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slot, planSlot);
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ExecClearTuple(slot);
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if (BufferIsValid(delbuffer))
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ReleaseBuffer(delbuffer);
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return rslot;
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}
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return NULL;
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}
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|
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/* ----------------------------------------------------------------
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* ExecUpdate
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*
|
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* note: we can't run UPDATE queries with transactions
|
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* off because UPDATEs are actually INSERTs and our
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* scan will mistakenly loop forever, updating the tuple
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* it just inserted.. This should be fixed but until it
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* is, we don't want to get stuck in an infinite loop
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* which corrupts your database..
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*
|
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* When updating a table, tupleid identifies the tuple to
|
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* update and oldtuple is NULL. When updating a view, oldtuple
|
|
* is passed to the INSTEAD OF triggers and identifies what to
|
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* update, and tupleid is invalid.
|
|
*
|
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* Returns RETURNING result if any, otherwise NULL.
|
|
* ----------------------------------------------------------------
|
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*/
|
|
static TupleTableSlot *
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ExecUpdate(ItemPointer tupleid,
|
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HeapTupleHeader oldtuple,
|
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TupleTableSlot *slot,
|
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TupleTableSlot *planSlot,
|
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EPQState *epqstate,
|
|
EState *estate,
|
|
bool canSetTag)
|
|
{
|
|
HeapTuple tuple;
|
|
ResultRelInfo *resultRelInfo;
|
|
Relation resultRelationDesc;
|
|
HTSU_Result result;
|
|
ItemPointerData update_ctid;
|
|
TransactionId update_xmax;
|
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List *recheckIndexes = NIL;
|
|
|
|
/*
|
|
* abort the operation if not running transactions
|
|
*/
|
|
if (IsBootstrapProcessingMode())
|
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elog(ERROR, "cannot UPDATE during bootstrap");
|
|
|
|
/*
|
|
* get the heap tuple out of the tuple table slot, making sure we have a
|
|
* writable copy
|
|
*/
|
|
tuple = ExecMaterializeSlot(slot);
|
|
|
|
/*
|
|
* get information on the (current) result relation
|
|
*/
|
|
resultRelInfo = estate->es_result_relation_info;
|
|
resultRelationDesc = resultRelInfo->ri_RelationDesc;
|
|
|
|
/* BEFORE ROW UPDATE Triggers */
|
|
if (resultRelInfo->ri_TrigDesc &&
|
|
resultRelInfo->ri_TrigDesc->trig_update_before_row)
|
|
{
|
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slot = ExecBRUpdateTriggers(estate, epqstate, resultRelInfo,
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tupleid, slot);
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|
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if (slot == NULL) /* "do nothing" */
|
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return NULL;
|
|
|
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/* trigger might have changed tuple */
|
|
tuple = ExecMaterializeSlot(slot);
|
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}
|
|
|
|
/* INSTEAD OF ROW UPDATE Triggers */
|
|
if (resultRelInfo->ri_TrigDesc &&
|
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resultRelInfo->ri_TrigDesc->trig_update_instead_row)
|
|
{
|
|
HeapTupleData oldtup;
|
|
|
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Assert(oldtuple != NULL);
|
|
oldtup.t_data = oldtuple;
|
|
oldtup.t_len = HeapTupleHeaderGetDatumLength(oldtuple);
|
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ItemPointerSetInvalid(&(oldtup.t_self));
|
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oldtup.t_tableOid = InvalidOid;
|
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|
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slot = ExecIRUpdateTriggers(estate, resultRelInfo,
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&oldtup, slot);
|
|
|
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if (slot == NULL) /* "do nothing" */
|
|
return NULL;
|
|
|
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/* trigger might have changed tuple */
|
|
tuple = ExecMaterializeSlot(slot);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Check the constraints of the tuple
|
|
*
|
|
* If we generate a new candidate tuple after EvalPlanQual testing, we
|
|
* must loop back here and recheck constraints. (We don't need to
|
|
* redo triggers, however. If there are any BEFORE triggers then
|
|
* trigger.c will have done heap_lock_tuple to lock the correct tuple,
|
|
* so there's no need to do them again.)
|
|
*/
|
|
lreplace:;
|
|
if (resultRelationDesc->rd_att->constr)
|
|
ExecConstraints(resultRelInfo, slot, estate);
|
|
|
|
/*
|
|
* replace the heap tuple
|
|
*
|
|
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check
|
|
* that the row to be updated is visible to that snapshot, and throw a
|
|
* can't-serialize error if not. This is a special-case behavior
|
|
* needed for referential integrity updates in transaction-snapshot
|
|
* mode transactions.
|
|
*/
|
|
result = heap_update(resultRelationDesc, tupleid, tuple,
|
|
&update_ctid, &update_xmax,
|
|
estate->es_output_cid,
|
|
estate->es_crosscheck_snapshot,
|
|
true /* wait for commit */ );
|
|
switch (result)
|
|
{
|
|
case HeapTupleSelfUpdated:
|
|
/* already deleted by self; nothing to do */
|
|
return NULL;
|
|
|
|
case HeapTupleMayBeUpdated:
|
|
break;
|
|
|
|
case HeapTupleUpdated:
|
|
if (IsolationUsesXactSnapshot())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
|
|
errmsg("could not serialize access due to concurrent update")));
|
|
if (!ItemPointerEquals(tupleid, &update_ctid))
|
|
{
|
|
TupleTableSlot *epqslot;
|
|
|
|
epqslot = EvalPlanQual(estate,
|
|
epqstate,
|
|
resultRelationDesc,
|
|
resultRelInfo->ri_RangeTableIndex,
|
|
&update_ctid,
|
|
update_xmax);
|
|
if (!TupIsNull(epqslot))
|
|
{
|
|
*tupleid = update_ctid;
|
|
slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot);
|
|
tuple = ExecMaterializeSlot(slot);
|
|
goto lreplace;
|
|
}
|
|
}
|
|
/* tuple already deleted; nothing to do */
|
|
return NULL;
|
|
|
|
default:
|
|
elog(ERROR, "unrecognized heap_update status: %u", result);
|
|
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 later by VACUUM (see notes in
|
|
* ExecDelete). All we do here is insert new index tuples. -cim
|
|
* 9/27/89
|
|
*/
|
|
|
|
/*
|
|
* insert index entries for tuple
|
|
*
|
|
* Note: heap_update returns the tid (location) of the new tuple in
|
|
* the t_self field.
|
|
*
|
|
* If it's a HOT update, we mustn't insert new index entries.
|
|
*/
|
|
if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tuple))
|
|
recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self),
|
|
estate);
|
|
}
|
|
|
|
if (canSetTag)
|
|
(estate->es_processed)++;
|
|
|
|
/* AFTER ROW UPDATE Triggers */
|
|
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple,
|
|
recheckIndexes);
|
|
|
|
list_free(recheckIndexes);
|
|
|
|
/* Process RETURNING if present */
|
|
if (resultRelInfo->ri_projectReturning)
|
|
return ExecProcessReturning(resultRelInfo->ri_projectReturning,
|
|
slot, planSlot);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Process BEFORE EACH STATEMENT triggers
|
|
*/
|
|
static void
|
|
fireBSTriggers(ModifyTableState *node)
|
|
{
|
|
switch (node->operation)
|
|
{
|
|
case CMD_INSERT:
|
|
ExecBSInsertTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
case CMD_UPDATE:
|
|
ExecBSUpdateTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
case CMD_DELETE:
|
|
ExecBSDeleteTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
default:
|
|
elog(ERROR, "unknown operation");
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Process AFTER EACH STATEMENT triggers
|
|
*/
|
|
static void
|
|
fireASTriggers(ModifyTableState *node)
|
|
{
|
|
switch (node->operation)
|
|
{
|
|
case CMD_INSERT:
|
|
ExecASInsertTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
case CMD_UPDATE:
|
|
ExecASUpdateTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
case CMD_DELETE:
|
|
ExecASDeleteTriggers(node->ps.state, node->resultRelInfo);
|
|
break;
|
|
default:
|
|
elog(ERROR, "unknown operation");
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecModifyTable
|
|
*
|
|
* Perform table modifications as required, and return RETURNING results
|
|
* if needed.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
TupleTableSlot *
|
|
ExecModifyTable(ModifyTableState *node)
|
|
{
|
|
EState *estate = node->ps.state;
|
|
CmdType operation = node->operation;
|
|
ResultRelInfo *saved_resultRelInfo;
|
|
ResultRelInfo *resultRelInfo;
|
|
PlanState *subplanstate;
|
|
JunkFilter *junkfilter;
|
|
TupleTableSlot *slot;
|
|
TupleTableSlot *planSlot;
|
|
ItemPointer tupleid = NULL;
|
|
ItemPointerData tuple_ctid;
|
|
HeapTupleHeader oldtuple = NULL;
|
|
|
|
/*
|
|
* If we've already completed processing, don't try to do more. We need
|
|
* this test because ExecPostprocessPlan might call us an extra time, and
|
|
* our subplan's nodes aren't necessarily robust against being called
|
|
* extra times.
|
|
*/
|
|
if (node->mt_done)
|
|
return NULL;
|
|
|
|
/*
|
|
* On first call, fire BEFORE STATEMENT triggers before proceeding.
|
|
*/
|
|
if (node->fireBSTriggers)
|
|
{
|
|
fireBSTriggers(node);
|
|
node->fireBSTriggers = false;
|
|
}
|
|
|
|
/* Preload local variables */
|
|
resultRelInfo = node->resultRelInfo + node->mt_whichplan;
|
|
subplanstate = node->mt_plans[node->mt_whichplan];
|
|
junkfilter = resultRelInfo->ri_junkFilter;
|
|
|
|
/*
|
|
* es_result_relation_info must point to the currently active result
|
|
* relation while we are within this ModifyTable node. Even though
|
|
* ModifyTable nodes can't be nested statically, they can be nested
|
|
* dynamically (since our subplan could include a reference to a modifying
|
|
* CTE). So we have to save and restore the caller's value.
|
|
*/
|
|
saved_resultRelInfo = estate->es_result_relation_info;
|
|
|
|
estate->es_result_relation_info = resultRelInfo;
|
|
|
|
/*
|
|
* Fetch rows from subplan(s), and execute the required table modification
|
|
* for each row.
|
|
*/
|
|
for (;;)
|
|
{
|
|
/*
|
|
* Reset the per-output-tuple exprcontext. This is needed because
|
|
* triggers expect to use that context as workspace. It's a bit ugly
|
|
* to do this below the top level of the plan, however. We might need
|
|
* to rethink this later.
|
|
*/
|
|
ResetPerTupleExprContext(estate);
|
|
|
|
planSlot = ExecProcNode(subplanstate);
|
|
|
|
if (TupIsNull(planSlot))
|
|
{
|
|
/* advance to next subplan if any */
|
|
node->mt_whichplan++;
|
|
if (node->mt_whichplan < node->mt_nplans)
|
|
{
|
|
resultRelInfo++;
|
|
subplanstate = node->mt_plans[node->mt_whichplan];
|
|
junkfilter = resultRelInfo->ri_junkFilter;
|
|
estate->es_result_relation_info = resultRelInfo;
|
|
EvalPlanQualSetPlan(&node->mt_epqstate, subplanstate->plan,
|
|
node->mt_arowmarks[node->mt_whichplan]);
|
|
continue;
|
|
}
|
|
else
|
|
break;
|
|
}
|
|
|
|
EvalPlanQualSetSlot(&node->mt_epqstate, planSlot);
|
|
slot = planSlot;
|
|
|
|
if (junkfilter != NULL)
|
|
{
|
|
/*
|
|
* extract the 'ctid' or 'wholerow' junk attribute.
|
|
*/
|
|
if (operation == CMD_UPDATE || operation == CMD_DELETE)
|
|
{
|
|
Datum datum;
|
|
bool isNull;
|
|
|
|
if (resultRelInfo->ri_RelationDesc->rd_rel->relkind == RELKIND_RELATION)
|
|
{
|
|
datum = ExecGetJunkAttribute(slot,
|
|
junkfilter->jf_junkAttNo,
|
|
&isNull);
|
|
/* shouldn't ever get a null result... */
|
|
if (isNull)
|
|
elog(ERROR, "ctid is NULL");
|
|
|
|
tupleid = (ItemPointer) DatumGetPointer(datum);
|
|
tuple_ctid = *tupleid; /* be sure we don't free ctid!! */
|
|
tupleid = &tuple_ctid;
|
|
}
|
|
else
|
|
{
|
|
datum = ExecGetJunkAttribute(slot,
|
|
junkfilter->jf_junkAttNo,
|
|
&isNull);
|
|
/* shouldn't ever get a null result... */
|
|
if (isNull)
|
|
elog(ERROR, "wholerow is NULL");
|
|
|
|
oldtuple = DatumGetHeapTupleHeader(datum);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* apply the junkfilter if needed.
|
|
*/
|
|
if (operation != CMD_DELETE)
|
|
slot = ExecFilterJunk(junkfilter, slot);
|
|
}
|
|
|
|
switch (operation)
|
|
{
|
|
case CMD_INSERT:
|
|
slot = ExecInsert(slot, planSlot, estate, node->canSetTag);
|
|
break;
|
|
case CMD_UPDATE:
|
|
slot = ExecUpdate(tupleid, oldtuple, slot, planSlot,
|
|
&node->mt_epqstate, estate, node->canSetTag);
|
|
break;
|
|
case CMD_DELETE:
|
|
slot = ExecDelete(tupleid, oldtuple, planSlot,
|
|
&node->mt_epqstate, estate, node->canSetTag);
|
|
break;
|
|
default:
|
|
elog(ERROR, "unknown operation");
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we got a RETURNING result, return it to caller. We'll continue
|
|
* the work on next call.
|
|
*/
|
|
if (slot)
|
|
{
|
|
estate->es_result_relation_info = saved_resultRelInfo;
|
|
return slot;
|
|
}
|
|
}
|
|
|
|
/* Restore es_result_relation_info before exiting */
|
|
estate->es_result_relation_info = saved_resultRelInfo;
|
|
|
|
/*
|
|
* We're done, but fire AFTER STATEMENT triggers before exiting.
|
|
*/
|
|
fireASTriggers(node);
|
|
|
|
node->mt_done = true;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecInitModifyTable
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
ModifyTableState *
|
|
ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
|
|
{
|
|
ModifyTableState *mtstate;
|
|
CmdType operation = node->operation;
|
|
int nplans = list_length(node->plans);
|
|
ResultRelInfo *saved_resultRelInfo;
|
|
ResultRelInfo *resultRelInfo;
|
|
TupleDesc tupDesc;
|
|
Plan *subplan;
|
|
ListCell *l;
|
|
int i;
|
|
|
|
/* check for unsupported flags */
|
|
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
|
|
|
|
/*
|
|
* This should NOT get called during EvalPlanQual; we should have passed a
|
|
* subplan tree to EvalPlanQual, instead. Use a runtime test not just
|
|
* Assert because this condition is easy to miss in testing ...
|
|
*/
|
|
if (estate->es_epqTuple != NULL)
|
|
elog(ERROR, "ModifyTable should not be called during EvalPlanQual");
|
|
|
|
/*
|
|
* create state structure
|
|
*/
|
|
mtstate = makeNode(ModifyTableState);
|
|
mtstate->ps.plan = (Plan *) node;
|
|
mtstate->ps.state = estate;
|
|
mtstate->ps.targetlist = NIL; /* not actually used */
|
|
|
|
mtstate->operation = operation;
|
|
mtstate->canSetTag = node->canSetTag;
|
|
mtstate->mt_done = false;
|
|
|
|
mtstate->mt_plans = (PlanState **) palloc0(sizeof(PlanState *) * nplans);
|
|
mtstate->resultRelInfo = estate->es_result_relations + node->resultRelIndex;
|
|
mtstate->mt_arowmarks = (List **) palloc0(sizeof(List *) * nplans);
|
|
mtstate->mt_nplans = nplans;
|
|
|
|
/* set up epqstate with dummy subplan data for the moment */
|
|
EvalPlanQualInit(&mtstate->mt_epqstate, estate, NULL, NIL, node->epqParam);
|
|
mtstate->fireBSTriggers = true;
|
|
|
|
/*
|
|
* call ExecInitNode on each of the plans to be executed and save the
|
|
* results into the array "mt_plans". This is also a convenient place
|
|
* to verify that the proposed target relations are valid and open their
|
|
* indexes for insertion of new index entries. Note we *must* set
|
|
* estate->es_result_relation_info correctly while we initialize each
|
|
* sub-plan; ExecContextForcesOids depends on that!
|
|
*/
|
|
saved_resultRelInfo = estate->es_result_relation_info;
|
|
|
|
resultRelInfo = mtstate->resultRelInfo;
|
|
i = 0;
|
|
foreach(l, node->plans)
|
|
{
|
|
subplan = (Plan *) lfirst(l);
|
|
|
|
/*
|
|
* Verify result relation is a valid target for the current operation
|
|
*/
|
|
CheckValidResultRel(resultRelInfo->ri_RelationDesc, operation);
|
|
|
|
/*
|
|
* If there are indices on the result relation, open them and save
|
|
* descriptors in the result relation info, so that we can add new
|
|
* index entries for the tuples we add/update. We need not do this
|
|
* for a DELETE, however, since deletion doesn't affect indexes.
|
|
*/
|
|
if (resultRelInfo->ri_RelationDesc->rd_rel->relhasindex &&
|
|
operation != CMD_DELETE)
|
|
ExecOpenIndices(resultRelInfo);
|
|
|
|
/* Now init the plan for this result rel */
|
|
estate->es_result_relation_info = resultRelInfo;
|
|
mtstate->mt_plans[i] = ExecInitNode(subplan, estate, eflags);
|
|
|
|
resultRelInfo++;
|
|
i++;
|
|
}
|
|
|
|
estate->es_result_relation_info = saved_resultRelInfo;
|
|
|
|
/*
|
|
* Initialize RETURNING projections if needed.
|
|
*/
|
|
if (node->returningLists)
|
|
{
|
|
TupleTableSlot *slot;
|
|
ExprContext *econtext;
|
|
|
|
/*
|
|
* Initialize result tuple slot and assign its rowtype using the first
|
|
* RETURNING list. We assume the rest will look the same.
|
|
*/
|
|
tupDesc = ExecTypeFromTL((List *) linitial(node->returningLists),
|
|
false);
|
|
|
|
/* Set up a slot for the output of the RETURNING projection(s) */
|
|
ExecInitResultTupleSlot(estate, &mtstate->ps);
|
|
ExecAssignResultType(&mtstate->ps, tupDesc);
|
|
slot = mtstate->ps.ps_ResultTupleSlot;
|
|
|
|
/* Need an econtext too */
|
|
econtext = CreateExprContext(estate);
|
|
mtstate->ps.ps_ExprContext = econtext;
|
|
|
|
/*
|
|
* Build a projection for each result rel.
|
|
*/
|
|
resultRelInfo = mtstate->resultRelInfo;
|
|
foreach(l, node->returningLists)
|
|
{
|
|
List *rlist = (List *) lfirst(l);
|
|
List *rliststate;
|
|
|
|
rliststate = (List *) ExecInitExpr((Expr *) rlist, &mtstate->ps);
|
|
resultRelInfo->ri_projectReturning =
|
|
ExecBuildProjectionInfo(rliststate, econtext, slot,
|
|
resultRelInfo->ri_RelationDesc->rd_att);
|
|
resultRelInfo++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We still must construct a dummy result tuple type, because InitPlan
|
|
* expects one (maybe should change that?).
|
|
*/
|
|
tupDesc = ExecTypeFromTL(NIL, false);
|
|
ExecInitResultTupleSlot(estate, &mtstate->ps);
|
|
ExecAssignResultType(&mtstate->ps, tupDesc);
|
|
|
|
mtstate->ps.ps_ExprContext = NULL;
|
|
}
|
|
|
|
/*
|
|
* If we have any secondary relations in an UPDATE or DELETE, they need to
|
|
* be treated like non-locked relations in SELECT FOR UPDATE, ie, the
|
|
* EvalPlanQual mechanism needs to be told about them. Locate the
|
|
* relevant ExecRowMarks.
|
|
*/
|
|
foreach(l, node->rowMarks)
|
|
{
|
|
PlanRowMark *rc = (PlanRowMark *) lfirst(l);
|
|
ExecRowMark *erm;
|
|
|
|
Assert(IsA(rc, PlanRowMark));
|
|
|
|
/* ignore "parent" rowmarks; they are irrelevant at runtime */
|
|
if (rc->isParent)
|
|
continue;
|
|
|
|
/* find ExecRowMark (same for all subplans) */
|
|
erm = ExecFindRowMark(estate, rc->rti);
|
|
|
|
/* build ExecAuxRowMark for each subplan */
|
|
for (i = 0; i < nplans; i++)
|
|
{
|
|
ExecAuxRowMark *aerm;
|
|
|
|
subplan = mtstate->mt_plans[i]->plan;
|
|
aerm = ExecBuildAuxRowMark(erm, subplan->targetlist);
|
|
mtstate->mt_arowmarks[i] = lappend(mtstate->mt_arowmarks[i], aerm);
|
|
}
|
|
}
|
|
|
|
/* select first subplan */
|
|
mtstate->mt_whichplan = 0;
|
|
subplan = (Plan *) linitial(node->plans);
|
|
EvalPlanQualSetPlan(&mtstate->mt_epqstate, subplan,
|
|
mtstate->mt_arowmarks[0]);
|
|
|
|
/*
|
|
* Initialize the junk filter(s) if needed. INSERT queries need a filter
|
|
* if there are any junk attrs in the tlist. UPDATE and DELETE always
|
|
* need a filter, since there's always a junk 'ctid' or 'wholerow'
|
|
* attribute present --- no need to look first.
|
|
*
|
|
* If there are multiple result relations, each one needs its own junk
|
|
* filter. Note multiple rels are only possible for UPDATE/DELETE, so we
|
|
* can't be fooled by some needing a filter and some not.
|
|
*
|
|
* This section of code is also a convenient place to verify that the
|
|
* output of an INSERT or UPDATE matches the target table(s).
|
|
*/
|
|
{
|
|
bool junk_filter_needed = false;
|
|
|
|
switch (operation)
|
|
{
|
|
case CMD_INSERT:
|
|
foreach(l, subplan->targetlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(l);
|
|
|
|
if (tle->resjunk)
|
|
{
|
|
junk_filter_needed = true;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
case CMD_UPDATE:
|
|
case CMD_DELETE:
|
|
junk_filter_needed = true;
|
|
break;
|
|
default:
|
|
elog(ERROR, "unknown operation");
|
|
break;
|
|
}
|
|
|
|
if (junk_filter_needed)
|
|
{
|
|
resultRelInfo = mtstate->resultRelInfo;
|
|
for (i = 0; i < nplans; i++)
|
|
{
|
|
JunkFilter *j;
|
|
|
|
subplan = mtstate->mt_plans[i]->plan;
|
|
if (operation == CMD_INSERT || operation == CMD_UPDATE)
|
|
ExecCheckPlanOutput(resultRelInfo->ri_RelationDesc,
|
|
subplan->targetlist);
|
|
|
|
j = ExecInitJunkFilter(subplan->targetlist,
|
|
resultRelInfo->ri_RelationDesc->rd_att->tdhasoid,
|
|
ExecInitExtraTupleSlot(estate));
|
|
|
|
if (operation == CMD_UPDATE || operation == CMD_DELETE)
|
|
{
|
|
/* For UPDATE/DELETE, find the appropriate junk attr now */
|
|
if (resultRelInfo->ri_RelationDesc->rd_rel->relkind == RELKIND_RELATION)
|
|
{
|
|
j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid");
|
|
if (!AttributeNumberIsValid(j->jf_junkAttNo))
|
|
elog(ERROR, "could not find junk ctid column");
|
|
}
|
|
else
|
|
{
|
|
j->jf_junkAttNo = ExecFindJunkAttribute(j, "wholerow");
|
|
if (!AttributeNumberIsValid(j->jf_junkAttNo))
|
|
elog(ERROR, "could not find junk wholerow column");
|
|
}
|
|
}
|
|
|
|
resultRelInfo->ri_junkFilter = j;
|
|
resultRelInfo++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (operation == CMD_INSERT)
|
|
ExecCheckPlanOutput(mtstate->resultRelInfo->ri_RelationDesc,
|
|
subplan->targetlist);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set up a tuple table slot for use for trigger output tuples. In a plan
|
|
* containing multiple ModifyTable nodes, all can share one such slot, so
|
|
* we keep it in the estate.
|
|
*/
|
|
if (estate->es_trig_tuple_slot == NULL)
|
|
estate->es_trig_tuple_slot = ExecInitExtraTupleSlot(estate);
|
|
|
|
/*
|
|
* Lastly, if this is not the primary (canSetTag) ModifyTable node, add it
|
|
* to estate->es_auxmodifytables so that it will be run to completion by
|
|
* ExecPostprocessPlan. (It'd actually work fine to add the primary
|
|
* ModifyTable node too, but there's no need.) Note the use of lcons
|
|
* not lappend: we need later-initialized ModifyTable nodes to be shut
|
|
* down before earlier ones. This ensures that we don't throw away
|
|
* RETURNING rows that need to be seen by a later CTE subplan.
|
|
*/
|
|
if (!mtstate->canSetTag)
|
|
estate->es_auxmodifytables = lcons(mtstate,
|
|
estate->es_auxmodifytables);
|
|
|
|
return mtstate;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------
|
|
* ExecEndModifyTable
|
|
*
|
|
* Shuts down the plan.
|
|
*
|
|
* Returns nothing of interest.
|
|
* ----------------------------------------------------------------
|
|
*/
|
|
void
|
|
ExecEndModifyTable(ModifyTableState *node)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Free the exprcontext
|
|
*/
|
|
ExecFreeExprContext(&node->ps);
|
|
|
|
/*
|
|
* clean out the tuple table
|
|
*/
|
|
ExecClearTuple(node->ps.ps_ResultTupleSlot);
|
|
|
|
/*
|
|
* Terminate EPQ execution if active
|
|
*/
|
|
EvalPlanQualEnd(&node->mt_epqstate);
|
|
|
|
/*
|
|
* shut down subplans
|
|
*/
|
|
for (i = 0; i < node->mt_nplans; i++)
|
|
ExecEndNode(node->mt_plans[i]);
|
|
}
|
|
|
|
void
|
|
ExecReScanModifyTable(ModifyTableState *node)
|
|
{
|
|
/*
|
|
* Currently, we don't need to support rescan on ModifyTable nodes. The
|
|
* semantics of that would be a bit debatable anyway.
|
|
*/
|
|
elog(ERROR, "ExecReScanModifyTable is not implemented");
|
|
}
|