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postgres/src/backend/executor/nodeModifyTable.c
Tom Lane c5b7ba4e67 Postpone some stuff out of ExecInitModifyTable. 
Arrange to do some things on-demand, rather than immediately during
executor startup, because there's a fair chance of never having to do
them at all:

* Don't open result relations' indexes until needed.

* Don't initialize partition tuple routing, nor the child-to-root
tuple conversion map, until needed.

This wins in UPDATEs on partitioned tables when only some of the
partitions will actually receive updates; with larger partition
counts the savings is quite noticeable.  Also, we can remove some
sketchy heuristics in ExecInitModifyTable about whether to set up
tuple routing.

Also, remove execPartition.c's private hash table tracking which
partitions were already opened by the ModifyTable node.  Instead
use the hash added to ModifyTable itself by commit 86dc90056.

To allow lazy computation of the conversion maps, we now set
ri_RootResultRelInfo in all child ResultRelInfos.  We formerly set it
only in some, not terribly well-defined, cases.  This has user-visible
side effects in that now more error messages refer to the root
relation instead of some partition (and provide error data in the
root's column order, too).  It looks to me like this is a strict
improvement in consistency, so I don't have a problem with the
output changes visible in this commit.

Extracted from a larger patch, which seemed to me to be too messy
to push in one commit.

Amit Langote, reviewed at different times by Heikki Linnakangas and
myself

Discussion: https://postgr.es/m/CA+HiwqG7ZruBmmih3wPsBZ4s0H2EhywrnXEduckY5Hr3fWzPWA@mail.gmail.com
2021-04-06 15:57:11 -04:00

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/*-------------------------------------------------------------------------
*
* nodeModifyTable.c
* routines to handle ModifyTable nodes.
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/executor/nodeModifyTable.c
*
*-------------------------------------------------------------------------
*/
/* INTERFACE ROUTINES
* ExecInitModifyTable - initialize the ModifyTable node
* ExecModifyTable - retrieve the next tuple from the node
* ExecEndModifyTable - shut down the ModifyTable node
* ExecReScanModifyTable - rescan the ModifyTable node
*
* NOTES
* The ModifyTable node receives input from its outerPlan, which is
* the data to insert for INSERT cases, or the changed columns' new
* values plus row-locating info for UPDATE cases, or just the
* row-locating info for DELETE cases.
*
* If the query specifies RETURNING, then the ModifyTable returns a
* RETURNING tuple after completing each row insert, update, or delete.
* It must be called again to continue the operation. Without RETURNING,
* we just loop within the node until all the work is done, then
* return NULL. This avoids useless call/return overhead.
*/
#include "postgres.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "commands/trigger.h"
#include "executor/execPartition.h"
#include "executor/executor.h"
#include "executor/nodeModifyTable.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "rewrite/rewriteHandler.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/memutils.h"
#include "utils/rel.h"
typedef struct MTTargetRelLookup
{
Oid relationOid; /* hash key, must be first */
int relationIndex; /* rel's index in resultRelInfo[] array */
} MTTargetRelLookup;
static void ExecBatchInsert(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
TupleTableSlot **slots,
TupleTableSlot **planSlots,
int numSlots,
EState *estate,
bool canSetTag);
static bool ExecOnConflictUpdate(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
ItemPointer conflictTid,
TupleTableSlot *planSlot,
TupleTableSlot *excludedSlot,
EState *estate,
bool canSetTag,
TupleTableSlot **returning);
static TupleTableSlot *ExecPrepareTupleRouting(ModifyTableState *mtstate,
EState *estate,
PartitionTupleRouting *proute,
ResultRelInfo *targetRelInfo,
TupleTableSlot *slot,
ResultRelInfo **partRelInfo);
/*
* Verify that the tuples to be produced by INSERT match the
* target relation's rowtype
*
* We do this to guard against stale plans. If plan invalidation is
* functioning properly then we should never get a failure here, but better
* safe than sorry. Note that this is called after we have obtained lock
* on the target rel, so the rowtype can't change underneath us.
*
* The plan output is represented by its targetlist, because that makes
* handling the dropped-column case easier.
*
* We used to use this for UPDATE as well, but now the equivalent checks
* are done in ExecBuildUpdateProjection.
*/
static void
ExecCheckPlanOutput(Relation resultRel, List *targetList)
{
TupleDesc resultDesc = RelationGetDescr(resultRel);
int attno = 0;
ListCell *lc;
foreach(lc, targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
Form_pg_attribute attr;
Assert(!tle->resjunk); /* caller removed junk items already */
if (attno >= resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query has too many columns.")));
attr = TupleDescAttr(resultDesc, attno);
attno++;
if (!attr->attisdropped)
{
/* Normal case: demand type match */
if (exprType((Node *) tle->expr) != attr->atttypid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Table has type %s at ordinal position %d, but query expects %s.",
format_type_be(attr->atttypid),
attno,
format_type_be(exprType((Node *) tle->expr)))));
}
else
{
/*
* For a dropped column, we can't check atttypid (it's likely 0).
* In any case the planner has most likely inserted an INT4 null.
* What we insist on is just *some* NULL constant.
*/
if (!IsA(tle->expr, Const) ||
!((Const *) tle->expr)->constisnull)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query provides a value for a dropped column at ordinal position %d.",
attno)));
}
}
if (attno != resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table row type and query-specified row type do not match"),
errdetail("Query has too few columns.")));
}
/*
* ExecProcessReturning --- evaluate a RETURNING list
*
* resultRelInfo: current result rel
* tupleSlot: slot holding tuple actually inserted/updated/deleted
* planSlot: slot holding tuple returned by top subplan node
*
* Note: If tupleSlot is NULL, the FDW should have already provided econtext's
* scan tuple.
*
* Returns a slot holding the result tuple
*/
static TupleTableSlot *
ExecProcessReturning(ResultRelInfo *resultRelInfo,
TupleTableSlot *tupleSlot,
TupleTableSlot *planSlot)
{
ProjectionInfo *projectReturning = resultRelInfo->ri_projectReturning;
ExprContext *econtext = projectReturning->pi_exprContext;
/* Make tuple and any needed join variables available to ExecProject */
if (tupleSlot)
econtext->ecxt_scantuple = tupleSlot;
econtext->ecxt_outertuple = planSlot;
/*
* RETURNING expressions might reference the tableoid column, so
* reinitialize tts_tableOid before evaluating them.
*/
econtext->ecxt_scantuple->tts_tableOid =
RelationGetRelid(resultRelInfo->ri_RelationDesc);
/* Compute the RETURNING expressions */
return ExecProject(projectReturning);
}
/*
* ExecCheckTupleVisible -- verify tuple is visible
*
* It would not be consistent with guarantees of the higher isolation levels to
* proceed with avoiding insertion (taking speculative insertion's alternative
* path) on the basis of another tuple that is not visible to MVCC snapshot.
* Check for the need to raise a serialization failure, and do so as necessary.
*/
static void
ExecCheckTupleVisible(EState *estate,
Relation rel,
TupleTableSlot *slot)
{
if (!IsolationUsesXactSnapshot())
return;
if (!table_tuple_satisfies_snapshot(rel, slot, estate->es_snapshot))
{
Datum xminDatum;
TransactionId xmin;
bool isnull;
xminDatum = slot_getsysattr(slot, MinTransactionIdAttributeNumber, &isnull);
Assert(!isnull);
xmin = DatumGetTransactionId(xminDatum);
/*
* We should not raise a serialization failure if the conflict is
* against a tuple inserted by our own transaction, even if it's not
* visible to our snapshot. (This would happen, for example, if
* conflicting keys are proposed for insertion in a single command.)
*/
if (!TransactionIdIsCurrentTransactionId(xmin))
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
}
}
/*
* ExecCheckTIDVisible -- convenience variant of ExecCheckTupleVisible()
*/
static void
ExecCheckTIDVisible(EState *estate,
ResultRelInfo *relinfo,
ItemPointer tid,
TupleTableSlot *tempSlot)
{
Relation rel = relinfo->ri_RelationDesc;
/* Redundantly check isolation level */
if (!IsolationUsesXactSnapshot())
return;
if (!table_tuple_fetch_row_version(rel, tid, SnapshotAny, tempSlot))
elog(ERROR, "failed to fetch conflicting tuple for ON CONFLICT");
ExecCheckTupleVisible(estate, rel, tempSlot);
ExecClearTuple(tempSlot);
}
/*
* Compute stored generated columns for a tuple
*/
void
ExecComputeStoredGenerated(ResultRelInfo *resultRelInfo,
EState *estate, TupleTableSlot *slot,
CmdType cmdtype)
{
Relation rel = resultRelInfo->ri_RelationDesc;
TupleDesc tupdesc = RelationGetDescr(rel);
int natts = tupdesc->natts;
MemoryContext oldContext;
Datum *values;
bool *nulls;
Assert(tupdesc->constr && tupdesc->constr->has_generated_stored);
/*
* If first time through for this result relation, build expression
* nodetrees for rel's stored generation expressions. Keep them in the
* per-query memory context so they'll survive throughout the query.
*/
if (resultRelInfo->ri_GeneratedExprs == NULL)
{
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
resultRelInfo->ri_GeneratedExprs =
(ExprState **) palloc(natts * sizeof(ExprState *));
resultRelInfo->ri_NumGeneratedNeeded = 0;
for (int i = 0; i < natts; i++)
{
if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_STORED)
{
Expr *expr;
/*
* If it's an update and the current column was not marked as
* being updated, then we can skip the computation. But if
* there is a BEFORE ROW UPDATE trigger, we cannot skip
* because the trigger might affect additional columns.
*/
if (cmdtype == CMD_UPDATE &&
!(rel->trigdesc && rel->trigdesc->trig_update_before_row) &&
!bms_is_member(i + 1 - FirstLowInvalidHeapAttributeNumber,
ExecGetExtraUpdatedCols(resultRelInfo, estate)))
{
resultRelInfo->ri_GeneratedExprs[i] = NULL;
continue;
}
expr = (Expr *) build_column_default(rel, i + 1);
if (expr == NULL)
elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
i + 1, RelationGetRelationName(rel));
resultRelInfo->ri_GeneratedExprs[i] = ExecPrepareExpr(expr, estate);
resultRelInfo->ri_NumGeneratedNeeded++;
}
}
MemoryContextSwitchTo(oldContext);
}
/*
* If no generated columns have been affected by this change, then skip
* the rest.
*/
if (resultRelInfo->ri_NumGeneratedNeeded == 0)
return;
oldContext = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
values = palloc(sizeof(*values) * natts);
nulls = palloc(sizeof(*nulls) * natts);
slot_getallattrs(slot);
memcpy(nulls, slot->tts_isnull, sizeof(*nulls) * natts);
for (int i = 0; i < natts; i++)
{
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
if (attr->attgenerated == ATTRIBUTE_GENERATED_STORED &&
resultRelInfo->ri_GeneratedExprs[i])
{
ExprContext *econtext;
Datum val;
bool isnull;
econtext = GetPerTupleExprContext(estate);
econtext->ecxt_scantuple = slot;
val = ExecEvalExpr(resultRelInfo->ri_GeneratedExprs[i], econtext, &isnull);
/*
* We must make a copy of val as we have no guarantees about where
* memory for a pass-by-reference Datum is located.
*/
if (!isnull)
val = datumCopy(val, attr->attbyval, attr->attlen);
values[i] = val;
nulls[i] = isnull;
}
else
{
if (!nulls[i])
values[i] = datumCopy(slot->tts_values[i], attr->attbyval, attr->attlen);
}
}
ExecClearTuple(slot);
memcpy(slot->tts_values, values, sizeof(*values) * natts);
memcpy(slot->tts_isnull, nulls, sizeof(*nulls) * natts);
ExecStoreVirtualTuple(slot);
ExecMaterializeSlot(slot);
MemoryContextSwitchTo(oldContext);
}
/*
* ExecGetInsertNewTuple
* This prepares a "new" tuple ready to be inserted into given result
* relation, by removing any junk columns of the plan's output tuple
* and (if necessary) coercing the tuple to the right tuple format.
*/
static TupleTableSlot *
ExecGetInsertNewTuple(ResultRelInfo *relinfo,
TupleTableSlot *planSlot)
{
ProjectionInfo *newProj = relinfo->ri_projectNew;
ExprContext *econtext;
/*
* If there's no projection to be done, just make sure the slot is of the
* right type for the target rel. If the planSlot is the right type we
* can use it as-is, else copy the data into ri_newTupleSlot.
*/
if (newProj == NULL)
{
if (relinfo->ri_newTupleSlot->tts_ops != planSlot->tts_ops)
{
ExecCopySlot(relinfo->ri_newTupleSlot, planSlot);
return relinfo->ri_newTupleSlot;
}
else
return planSlot;
}
/*
* Else project; since the projection output slot is ri_newTupleSlot, this
* will also fix any slot-type problem.
*
* Note: currently, this is dead code, because INSERT cases don't receive
* any junk columns so there's never a projection to be done.
*/
econtext = newProj->pi_exprContext;
econtext->ecxt_outertuple = planSlot;
return ExecProject(newProj);
}
/*
* ExecGetUpdateNewTuple
* This prepares a "new" tuple by combining an UPDATE subplan's output
* tuple (which contains values of changed columns) with unchanged
* columns taken from the old tuple.
*
* The subplan tuple might also contain junk columns, which are ignored.
* Note that the projection also ensures we have a slot of the right type.
*/
TupleTableSlot *
ExecGetUpdateNewTuple(ResultRelInfo *relinfo,
TupleTableSlot *planSlot,
TupleTableSlot *oldSlot)
{
ProjectionInfo *newProj = relinfo->ri_projectNew;
ExprContext *econtext;
Assert(planSlot != NULL && !TTS_EMPTY(planSlot));
Assert(oldSlot != NULL && !TTS_EMPTY(oldSlot));
econtext = newProj->pi_exprContext;
econtext->ecxt_outertuple = planSlot;
econtext->ecxt_scantuple = oldSlot;
return ExecProject(newProj);
}
/* ----------------------------------------------------------------
* ExecInsert
*
* For INSERT, we have to insert the tuple into the target relation
* (or partition thereof) and insert appropriate tuples into the index
* relations.
*
* slot contains the new tuple value to be stored.
* planSlot is the output of the ModifyTable's subplan; we use it
* to access "junk" columns that are not going to be stored.
*
* Returns RETURNING result if any, otherwise NULL.
*
* This may change the currently active tuple conversion map in
* mtstate->mt_transition_capture, so the callers must take care to
* save the previous value to avoid losing track of it.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecInsert(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
TupleTableSlot *slot,
TupleTableSlot *planSlot,
EState *estate,
bool canSetTag)
{
Relation resultRelationDesc;
List *recheckIndexes = NIL;
TupleTableSlot *result = NULL;
TransitionCaptureState *ar_insert_trig_tcs;
ModifyTable *node = (ModifyTable *) mtstate->ps.plan;
OnConflictAction onconflict = node->onConflictAction;
PartitionTupleRouting *proute = mtstate->mt_partition_tuple_routing;
MemoryContext oldContext;
/*
* If the input result relation is a partitioned table, find the leaf
* partition to insert the tuple into.
*/
if (proute)
{
ResultRelInfo *partRelInfo;
slot = ExecPrepareTupleRouting(mtstate, estate, proute,
resultRelInfo, slot,
&partRelInfo);
resultRelInfo = partRelInfo;
}
ExecMaterializeSlot(slot);
resultRelationDesc = resultRelInfo->ri_RelationDesc;
/*
* Open the table's indexes, if we have not done so already, so that we
* can add new index entries for the inserted tuple.
*/
if (resultRelationDesc->rd_rel->relhasindex &&
resultRelInfo->ri_IndexRelationDescs == NULL)
ExecOpenIndices(resultRelInfo, onconflict != ONCONFLICT_NONE);
/*
* BEFORE ROW INSERT Triggers.
*
* Note: We fire BEFORE ROW TRIGGERS for every attempted insertion in an
* INSERT ... ON CONFLICT statement. We cannot check for constraint
* violations before firing these triggers, because they can change the
* values to insert. Also, they can run arbitrary user-defined code with
* side-effects that we can't cancel by just not inserting the tuple.
*/
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_insert_before_row)
{
if (!ExecBRInsertTriggers(estate, resultRelInfo, slot))
return NULL; /* "do nothing" */
}
/* INSTEAD OF ROW INSERT Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_insert_instead_row)
{
if (!ExecIRInsertTriggers(estate, resultRelInfo, slot))
return NULL; /* "do nothing" */
}
else if (resultRelInfo->ri_FdwRoutine)
{
/*
* Compute stored generated columns
*/
if (resultRelationDesc->rd_att->constr &&
resultRelationDesc->rd_att->constr->has_generated_stored)
ExecComputeStoredGenerated(resultRelInfo, estate, slot,
CMD_INSERT);
/*
* If the FDW supports batching, and batching is requested, accumulate
* rows and insert them in batches. Otherwise use the per-row inserts.
*/
if (resultRelInfo->ri_BatchSize > 1)
{
/*
* If a certain number of tuples have already been accumulated,
* or a tuple has come for a different relation than that for
* the accumulated tuples, perform the batch insert
*/
if (resultRelInfo->ri_NumSlots == resultRelInfo->ri_BatchSize)
{
ExecBatchInsert(mtstate, resultRelInfo,
resultRelInfo->ri_Slots,
resultRelInfo->ri_PlanSlots,
resultRelInfo->ri_NumSlots,
estate, canSetTag);
resultRelInfo->ri_NumSlots = 0;
}
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
if (resultRelInfo->ri_Slots == NULL)
{
resultRelInfo->ri_Slots = palloc(sizeof(TupleTableSlot *) *
resultRelInfo->ri_BatchSize);
resultRelInfo->ri_PlanSlots = palloc(sizeof(TupleTableSlot *) *
resultRelInfo->ri_BatchSize);
}
resultRelInfo->ri_Slots[resultRelInfo->ri_NumSlots] =
MakeSingleTupleTableSlot(slot->tts_tupleDescriptor,
slot->tts_ops);
ExecCopySlot(resultRelInfo->ri_Slots[resultRelInfo->ri_NumSlots],
slot);
resultRelInfo->ri_PlanSlots[resultRelInfo->ri_NumSlots] =
MakeSingleTupleTableSlot(planSlot->tts_tupleDescriptor,
planSlot->tts_ops);
ExecCopySlot(resultRelInfo->ri_PlanSlots[resultRelInfo->ri_NumSlots],
planSlot);
resultRelInfo->ri_NumSlots++;
MemoryContextSwitchTo(oldContext);
return NULL;
}
/*
* insert into foreign table: let the FDW do it
*/
slot = resultRelInfo->ri_FdwRoutine->ExecForeignInsert(estate,
resultRelInfo,
slot,
planSlot);
if (slot == NULL) /* "do nothing" */
return NULL;
/*
* AFTER ROW Triggers or RETURNING expressions might reference the
* tableoid column, so (re-)initialize tts_tableOid before evaluating
* them.
*/
slot->tts_tableOid = RelationGetRelid(resultRelInfo->ri_RelationDesc);
}
else
{
WCOKind wco_kind;
/*
* Constraints might reference the tableoid column, so (re-)initialize
* tts_tableOid before evaluating them.
*/
slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
/*
* Compute stored generated columns
*/
if (resultRelationDesc->rd_att->constr &&
resultRelationDesc->rd_att->constr->has_generated_stored)
ExecComputeStoredGenerated(resultRelInfo, estate, slot,
CMD_INSERT);
/*
* Check any RLS WITH CHECK policies.
*
* Normally we should check INSERT policies. But if the insert is the
* result of a partition key update that moved the tuple to a new
* partition, we should instead check UPDATE policies, because we are
* executing policies defined on the target table, and not those
* defined on the child partitions.
*/
wco_kind = (mtstate->operation == CMD_UPDATE) ?
WCO_RLS_UPDATE_CHECK : WCO_RLS_INSERT_CHECK;
/*
* ExecWithCheckOptions() will skip any WCOs which are not of the kind
* we are looking for at this point.
*/
if (resultRelInfo->ri_WithCheckOptions != NIL)
ExecWithCheckOptions(wco_kind, resultRelInfo, slot, estate);
/*
* Check the constraints of the tuple.
*/
if (resultRelationDesc->rd_att->constr)
ExecConstraints(resultRelInfo, slot, estate);
/*
* Also check the tuple against the partition constraint, if there is
* one; except that if we got here via tuple-routing, we don't need to
* if there's no BR trigger defined on the partition.
*/
if (resultRelationDesc->rd_rel->relispartition &&
(resultRelInfo->ri_RootResultRelInfo == NULL ||
(resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_insert_before_row)))
ExecPartitionCheck(resultRelInfo, slot, estate, true);
if (onconflict != ONCONFLICT_NONE && resultRelInfo->ri_NumIndices > 0)
{
/* Perform a speculative insertion. */
uint32 specToken;
ItemPointerData conflictTid;
bool specConflict;
List *arbiterIndexes;
arbiterIndexes = resultRelInfo->ri_onConflictArbiterIndexes;
/*
* Do a non-conclusive check for conflicts first.
*
* We're not holding any locks yet, so this doesn't guarantee that
* the later insert won't conflict. But it avoids leaving behind
* a lot of canceled speculative insertions, if you run a lot of
* INSERT ON CONFLICT statements that do conflict.
*
* We loop back here if we find a conflict below, either during
* the pre-check, or when we re-check after inserting the tuple
* speculatively.
*/
vlock:
specConflict = false;
if (!ExecCheckIndexConstraints(resultRelInfo, slot, estate,
&conflictTid, arbiterIndexes))
{
/* committed conflict tuple found */
if (onconflict == ONCONFLICT_UPDATE)
{
/*
* In case of ON CONFLICT DO UPDATE, execute the UPDATE
* part. Be prepared to retry if the UPDATE fails because
* of another concurrent UPDATE/DELETE to the conflict
* tuple.
*/
TupleTableSlot *returning = NULL;
if (ExecOnConflictUpdate(mtstate, resultRelInfo,
&conflictTid, planSlot, slot,
estate, canSetTag, &returning))
{
InstrCountTuples2(&mtstate->ps, 1);
return returning;
}
else
goto vlock;
}
else
{
/*
* In case of ON CONFLICT DO NOTHING, do nothing. However,
* verify that the tuple is visible to the executor's MVCC
* snapshot at higher isolation levels.
*
* Using ExecGetReturningSlot() to store the tuple for the
* recheck isn't that pretty, but we can't trivially use
* the input slot, because it might not be of a compatible
* type. As there's no conflicting usage of
* ExecGetReturningSlot() in the DO NOTHING case...
*/
Assert(onconflict == ONCONFLICT_NOTHING);
ExecCheckTIDVisible(estate, resultRelInfo, &conflictTid,
ExecGetReturningSlot(estate, resultRelInfo));
InstrCountTuples2(&mtstate->ps, 1);
return NULL;
}
}
/*
* Before we start insertion proper, acquire our "speculative
* insertion lock". Others can use that to wait for us to decide
* if we're going to go ahead with the insertion, instead of
* waiting for the whole transaction to complete.
*/
specToken = SpeculativeInsertionLockAcquire(GetCurrentTransactionId());
/* insert the tuple, with the speculative token */
table_tuple_insert_speculative(resultRelationDesc, slot,
estate->es_output_cid,
0,
NULL,
specToken);
/* insert index entries for tuple */
recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
slot, estate, false, true,
&specConflict,
arbiterIndexes);
/* adjust the tuple's state accordingly */
table_tuple_complete_speculative(resultRelationDesc, slot,
specToken, !specConflict);
/*
* Wake up anyone waiting for our decision. They will re-check
* the tuple, see that it's no longer speculative, and wait on our
* XID as if this was a regularly inserted tuple all along. Or if
* we killed the tuple, they will see it's dead, and proceed as if
* the tuple never existed.
*/
SpeculativeInsertionLockRelease(GetCurrentTransactionId());
/*
* If there was a conflict, start from the beginning. We'll do
* the pre-check again, which will now find the conflicting tuple
* (unless it aborts before we get there).
*/
if (specConflict)
{
list_free(recheckIndexes);
goto vlock;
}
/* Since there was no insertion conflict, we're done */
}
else
{
/* insert the tuple normally */
table_tuple_insert(resultRelationDesc, slot,
estate->es_output_cid,
0, NULL);
/* insert index entries for tuple */
if (resultRelInfo->ri_NumIndices > 0)
recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
slot, estate, false,
false, NULL, NIL);
}
}
if (canSetTag)
(estate->es_processed)++;
/*
* If this insert is the result of a partition key update that moved the
* tuple to a new partition, put this row into the transition NEW TABLE,
* if there is one. We need to do this separately for DELETE and INSERT
* because they happen on different tables.
*/
ar_insert_trig_tcs = mtstate->mt_transition_capture;
if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture
&& mtstate->mt_transition_capture->tcs_update_new_table)
{
ExecARUpdateTriggers(estate, resultRelInfo, NULL,
NULL,
slot,
NULL,
mtstate->mt_transition_capture);
/*
* We've already captured the NEW TABLE row, so make sure any AR
* INSERT trigger fired below doesn't capture it again.
*/
ar_insert_trig_tcs = NULL;
}
/* AFTER ROW INSERT Triggers */
ExecARInsertTriggers(estate, resultRelInfo, slot, recheckIndexes,
ar_insert_trig_tcs);
list_free(recheckIndexes);
/*
* Check any WITH CHECK OPTION constraints from parent views. We are
* required to do this after testing all constraints and uniqueness
* violations per the SQL spec, so we do it after actually inserting the
* record into the heap and all indexes.
*
* ExecWithCheckOptions will elog(ERROR) if a violation is found, so the
* tuple will never be seen, if it violates the WITH CHECK OPTION.
*
* ExecWithCheckOptions() will skip any WCOs which are not of the kind we
* are looking for at this point.
*/
if (resultRelInfo->ri_WithCheckOptions != NIL)
ExecWithCheckOptions(WCO_VIEW_CHECK, resultRelInfo, slot, estate);
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
result = ExecProcessReturning(resultRelInfo, slot, planSlot);
return result;
}
/* ----------------------------------------------------------------
* ExecBatchInsert
*
* Insert multiple tuples in an efficient way.
* Currently, this handles inserting into a foreign table without
* RETURNING clause.
* ----------------------------------------------------------------
*/
static void
ExecBatchInsert(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
TupleTableSlot **slots,
TupleTableSlot **planSlots,
int numSlots,
EState *estate,
bool canSetTag)
{
int i;
int numInserted = numSlots;
TupleTableSlot *slot = NULL;
TupleTableSlot **rslots;
/*
* insert into foreign table: let the FDW do it
*/
rslots = resultRelInfo->ri_FdwRoutine->ExecForeignBatchInsert(estate,
resultRelInfo,
slots,
planSlots,
&numInserted);
for (i = 0; i < numInserted; i++)
{
slot = rslots[i];
/*
* AFTER ROW Triggers or RETURNING expressions might reference the
* tableoid column, so (re-)initialize tts_tableOid before evaluating
* them.
*/
slot->tts_tableOid = RelationGetRelid(resultRelInfo->ri_RelationDesc);
/* AFTER ROW INSERT Triggers */
ExecARInsertTriggers(estate, resultRelInfo, slot, NIL,
mtstate->mt_transition_capture);
/*
* Check any WITH CHECK OPTION constraints from parent views. See the
* comment in ExecInsert.
*/
if (resultRelInfo->ri_WithCheckOptions != NIL)
ExecWithCheckOptions(WCO_VIEW_CHECK, resultRelInfo, slot, estate);
}
if (canSetTag && numInserted > 0)
estate->es_processed += numInserted;
for (i = 0; i < numSlots; i++)
{
ExecDropSingleTupleTableSlot(slots[i]);
ExecDropSingleTupleTableSlot(planSlots[i]);
}
}
/* ----------------------------------------------------------------
* ExecDelete
*
* DELETE is like UPDATE, except that we delete the tuple and no
* index modifications are needed.
*
* When deleting from a table, tupleid identifies the tuple to
* delete and oldtuple is NULL. When deleting from a view,
* oldtuple is passed to the INSTEAD OF triggers and identifies
* what to delete, and tupleid is invalid. When deleting from a
* foreign table, tupleid is invalid; the FDW has to figure out
* which row to delete using data from the planSlot. oldtuple is
* passed to foreign table triggers; it is NULL when the foreign
* table has no relevant triggers. We use tupleDeleted to indicate
* whether the tuple is actually deleted, callers can use it to
* decide whether to continue the operation. When this DELETE is a
* part of an UPDATE of partition-key, then the slot returned by
* EvalPlanQual() is passed back using output parameter epqslot.
*
* Returns RETURNING result if any, otherwise NULL.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecDelete(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
ItemPointer tupleid,
HeapTuple oldtuple,
TupleTableSlot *planSlot,
EPQState *epqstate,
EState *estate,
bool processReturning,
bool canSetTag,
bool changingPart,
bool *tupleDeleted,
TupleTableSlot **epqreturnslot)
{
Relation resultRelationDesc = resultRelInfo->ri_RelationDesc;
TM_Result result;
TM_FailureData tmfd;
TupleTableSlot *slot = NULL;
TransitionCaptureState *ar_delete_trig_tcs;
if (tupleDeleted)
*tupleDeleted = false;
/* BEFORE ROW DELETE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_delete_before_row)
{
bool dodelete;
dodelete = ExecBRDeleteTriggers(estate, epqstate, resultRelInfo,
tupleid, oldtuple, epqreturnslot);
if (!dodelete) /* "do nothing" */
return NULL;
}
/* INSTEAD OF ROW DELETE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_delete_instead_row)
{
bool dodelete;
Assert(oldtuple != NULL);
dodelete = ExecIRDeleteTriggers(estate, resultRelInfo, oldtuple);
if (!dodelete) /* "do nothing" */
return NULL;
}
else if (resultRelInfo->ri_FdwRoutine)
{
/*
* delete from foreign table: let the FDW do it
*
* We offer the returning slot as a place to store RETURNING data,
* although the FDW can return some other slot if it wants.
*/
slot = ExecGetReturningSlot(estate, resultRelInfo);
slot = resultRelInfo->ri_FdwRoutine->ExecForeignDelete(estate,
resultRelInfo,
slot,
planSlot);
if (slot == NULL) /* "do nothing" */
return NULL;
/*
* RETURNING expressions might reference the tableoid column, so
* (re)initialize tts_tableOid before evaluating them.
*/
if (TTS_EMPTY(slot))
ExecStoreAllNullTuple(slot);
slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
}
else
{
/*
* delete the tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check
* that the row to be deleted is visible to that snapshot, and throw a
* can't-serialize error if not. This is a special-case behavior
* needed for referential integrity updates in transaction-snapshot
* mode transactions.
*/
ldelete:;
result = table_tuple_delete(resultRelationDesc, tupleid,
estate->es_output_cid,
estate->es_snapshot,
estate->es_crosscheck_snapshot,
true /* wait for commit */ ,
&tmfd,
changingPart);
switch (result)
{
case TM_SelfModified:
/*
* The target tuple was already updated or deleted by the
* current command, or by a later command in the current
* transaction. The former case is possible in a join DELETE
* where multiple tuples join to the same target tuple. This
* is somewhat questionable, but Postgres has always allowed
* it: we just ignore additional deletion attempts.
*
* The latter case arises if the tuple is modified by a
* command in a BEFORE trigger, or perhaps by a command in a
* volatile function used in the query. In such situations we
* should not ignore the deletion, but it is equally unsafe to
* proceed. We don't want to discard the original DELETE
* while keeping the triggered actions based on its deletion;
* and it would be no better to allow the original DELETE
* while discarding updates that it triggered. The row update
* carries some information that might be important according
* to business rules; so throwing an error is the only safe
* course.
*
* If a trigger actually intends this type of interaction, it
* can re-execute the DELETE and then return NULL to cancel
* the outer delete.
*/
if (tmfd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be deleted was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
/* Else, already deleted by self; nothing to do */
return NULL;
case TM_Ok:
break;
case TM_Updated:
{
TupleTableSlot *inputslot;
TupleTableSlot *epqslot;
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
/*
* Already know that we're going to need to do EPQ, so
* fetch tuple directly into the right slot.
*/
EvalPlanQualBegin(epqstate);
inputslot = EvalPlanQualSlot(epqstate, resultRelationDesc,
resultRelInfo->ri_RangeTableIndex);
result = table_tuple_lock(resultRelationDesc, tupleid,
estate->es_snapshot,
inputslot, estate->es_output_cid,
LockTupleExclusive, LockWaitBlock,
TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
&tmfd);
switch (result)
{
case TM_Ok:
Assert(tmfd.traversed);
epqslot = EvalPlanQual(epqstate,
resultRelationDesc,
resultRelInfo->ri_RangeTableIndex,
inputslot);
if (TupIsNull(epqslot))
/* Tuple not passing quals anymore, exiting... */
return NULL;
/*
* If requested, skip delete and pass back the
* updated row.
*/
if (epqreturnslot)
{
*epqreturnslot = epqslot;
return NULL;
}
else
goto ldelete;
case TM_SelfModified:
/*
* This can be reached when following an update
* chain from a tuple updated by another session,
* reaching a tuple that was already updated in
* this transaction. If previously updated by this
* command, ignore the delete, otherwise error
* out.
*
* See also TM_SelfModified response to
* table_tuple_delete() above.
*/
if (tmfd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be deleted was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
return NULL;
case TM_Deleted:
/* tuple already deleted; nothing to do */
return NULL;
default:
/*
* TM_Invisible should be impossible because we're
* waiting for updated row versions, and would
* already have errored out if the first version
* is invisible.
*
* TM_Updated should be impossible, because we're
* locking the latest version via
* TUPLE_LOCK_FLAG_FIND_LAST_VERSION.
*/
elog(ERROR, "unexpected table_tuple_lock status: %u",
result);
return NULL;
}
Assert(false);
break;
}
case TM_Deleted:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent delete")));
/* tuple already deleted; nothing to do */
return NULL;
default:
elog(ERROR, "unrecognized table_tuple_delete status: %u",
result);
return NULL;
}
/*
* Note: Normally one would think that we have to delete index tuples
* associated with the heap tuple now...
*
* ... but in POSTGRES, we have no need to do this because VACUUM will
* take care of it later. We can't delete index tuples immediately
* anyway, since the tuple is still visible to other transactions.
*/
}
if (canSetTag)
(estate->es_processed)++;
/* Tell caller that the delete actually happened. */
if (tupleDeleted)
*tupleDeleted = true;
/*
* If this delete is the result of a partition key update that moved the
* tuple to a new partition, put this row into the transition OLD TABLE,
* if there is one. We need to do this separately for DELETE and INSERT
* because they happen on different tables.
*/
ar_delete_trig_tcs = mtstate->mt_transition_capture;
if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture
&& mtstate->mt_transition_capture->tcs_update_old_table)
{
ExecARUpdateTriggers(estate, resultRelInfo,
tupleid,
oldtuple,
NULL,
NULL,
mtstate->mt_transition_capture);
/*
* We've already captured the NEW TABLE row, so make sure any AR
* DELETE trigger fired below doesn't capture it again.
*/
ar_delete_trig_tcs = NULL;
}
/* AFTER ROW DELETE Triggers */
ExecARDeleteTriggers(estate, resultRelInfo, tupleid, oldtuple,
ar_delete_trig_tcs);
/* Process RETURNING if present and if requested */
if (processReturning && resultRelInfo->ri_projectReturning)
{
/*
* We have to put the target tuple into a slot, which means first we
* gotta fetch it. We can use the trigger tuple slot.
*/
TupleTableSlot *rslot;
if (resultRelInfo->ri_FdwRoutine)
{
/* FDW must have provided a slot containing the deleted row */
Assert(!TupIsNull(slot));
}
else
{
slot = ExecGetReturningSlot(estate, resultRelInfo);
if (oldtuple != NULL)
{
ExecForceStoreHeapTuple(oldtuple, slot, false);
}
else
{
if (!table_tuple_fetch_row_version(resultRelationDesc, tupleid,
SnapshotAny, slot))
elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING");
}
}
rslot = ExecProcessReturning(resultRelInfo, slot, planSlot);
/*
* Before releasing the target tuple again, make sure rslot has a
* local copy of any pass-by-reference values.
*/
ExecMaterializeSlot(rslot);
ExecClearTuple(slot);
return rslot;
}
return NULL;
}
/*
* ExecCrossPartitionUpdate --- Move an updated tuple to another partition.
*
* This works by first deleting the old tuple from the current partition,
* followed by inserting the new tuple into the root parent table, that is,
* mtstate->rootResultRelInfo. It will be re-routed from there to the
* correct partition.
*
* Returns true if the tuple has been successfully moved, or if it's found
* that the tuple was concurrently deleted so there's nothing more to do
* for the caller.
*
* False is returned if the tuple we're trying to move is found to have been
* concurrently updated. In that case, the caller must to check if the
* updated tuple that's returned in *retry_slot still needs to be re-routed,
* and call this function again or perform a regular update accordingly.
*/
static bool
ExecCrossPartitionUpdate(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
ItemPointer tupleid, HeapTuple oldtuple,
TupleTableSlot *slot, TupleTableSlot *planSlot,
EPQState *epqstate, bool canSetTag,
TupleTableSlot **retry_slot,
TupleTableSlot **inserted_tuple)
{
EState *estate = mtstate->ps.state;
TupleConversionMap *tupconv_map;
bool tuple_deleted;
TupleTableSlot *epqslot = NULL;
*inserted_tuple = NULL;
*retry_slot = NULL;
/*
* Disallow an INSERT ON CONFLICT DO UPDATE that causes the original row
* to migrate to a different partition. Maybe this can be implemented
* some day, but it seems a fringe feature with little redeeming value.
*/
if (((ModifyTable *) mtstate->ps.plan)->onConflictAction == ONCONFLICT_UPDATE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("invalid ON UPDATE specification"),
errdetail("The result tuple would appear in a different partition than the original tuple.")));
/*
* When an UPDATE is run directly on a leaf partition, simply fail with a
* partition constraint violation error.
*/
if (resultRelInfo == mtstate->rootResultRelInfo)
ExecPartitionCheckEmitError(resultRelInfo, slot, estate);
/* Initialize tuple routing info if not already done. */
if (mtstate->mt_partition_tuple_routing == NULL)
{
Relation rootRel = mtstate->rootResultRelInfo->ri_RelationDesc;
MemoryContext oldcxt;
/* Things built here have to last for the query duration. */
oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
mtstate->mt_partition_tuple_routing =
ExecSetupPartitionTupleRouting(estate, rootRel);
/*
* Before a partition's tuple can be re-routed, it must first be
* converted to the root's format, so we'll need a slot for storing
* such tuples.
*/
Assert(mtstate->mt_root_tuple_slot == NULL);
mtstate->mt_root_tuple_slot = table_slot_create(rootRel, NULL);
MemoryContextSwitchTo(oldcxt);
}
/*
* Row movement, part 1. Delete the tuple, but skip RETURNING processing.
* We want to return rows from INSERT.
*/
ExecDelete(mtstate, resultRelInfo, tupleid, oldtuple, planSlot,
epqstate, estate,
false, /* processReturning */
false, /* canSetTag */
true, /* changingPart */
&tuple_deleted, &epqslot);
/*
* For some reason if DELETE didn't happen (e.g. trigger prevented it, or
* it was already deleted by self, or it was concurrently deleted by
* another transaction), then we should skip the insert as well;
* otherwise, an UPDATE could cause an increase in the total number of
* rows across all partitions, which is clearly wrong.
*
* For a normal UPDATE, the case where the tuple has been the subject of a
* concurrent UPDATE or DELETE would be handled by the EvalPlanQual
* machinery, but for an UPDATE that we've translated into a DELETE from
* this partition and an INSERT into some other partition, that's not
* available, because CTID chains can't span relation boundaries. We
* mimic the semantics to a limited extent by skipping the INSERT if the
* DELETE fails to find a tuple. This ensures that two concurrent
* attempts to UPDATE the same tuple at the same time can't turn one tuple
* into two, and that an UPDATE of a just-deleted tuple can't resurrect
* it.
*/
if (!tuple_deleted)
{
/*
* epqslot will be typically NULL. But when ExecDelete() finds that
* another transaction has concurrently updated the same row, it
* re-fetches the row, skips the delete, and epqslot is set to the
* re-fetched tuple slot. In that case, we need to do all the checks
* again.
*/
if (TupIsNull(epqslot))
return true;
else
{
/* Fetch the most recent version of old tuple. */
TupleTableSlot *oldSlot = resultRelInfo->ri_oldTupleSlot;
if (!table_tuple_fetch_row_version(resultRelInfo->ri_RelationDesc,
tupleid,
SnapshotAny,
oldSlot))
elog(ERROR, "failed to fetch tuple being updated");
*retry_slot = ExecGetUpdateNewTuple(resultRelInfo, epqslot,
oldSlot);
return false;
}
}
/*
* resultRelInfo is one of the per-relation resultRelInfos. So we should
* convert the tuple into root's tuple descriptor if needed, since
* ExecInsert() starts the search from root.
*/
tupconv_map = ExecGetChildToRootMap(resultRelInfo);
if (tupconv_map != NULL)
slot = execute_attr_map_slot(tupconv_map->attrMap,
slot,
mtstate->mt_root_tuple_slot);
/* Tuple routing starts from the root table. */
*inserted_tuple = ExecInsert(mtstate, mtstate->rootResultRelInfo, slot,
planSlot, estate, canSetTag);
/*
* Reset the transition state that may possibly have been written by
* INSERT.
*/
if (mtstate->mt_transition_capture)
mtstate->mt_transition_capture->tcs_original_insert_tuple = NULL;
/* We're done moving. */
return true;
}
/* ----------------------------------------------------------------
* 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..
*
* When updating a table, tupleid identifies the tuple to
* update and oldtuple is NULL. When updating a view, oldtuple
* is passed to the INSTEAD OF triggers and identifies what to
* update, and tupleid is invalid. When updating a foreign table,
* tupleid is invalid; the FDW has to figure out which row to
* update using data from the planSlot. oldtuple is passed to
* foreign table triggers; it is NULL when the foreign table has
* no relevant triggers.
*
* slot contains the new tuple value to be stored.
* planSlot is the output of the ModifyTable's subplan; we use it
* to access values from other input tables (for RETURNING),
* row-ID junk columns, etc.
*
* Returns RETURNING result if any, otherwise NULL.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecUpdate(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
ItemPointer tupleid,
HeapTuple oldtuple,
TupleTableSlot *slot,
TupleTableSlot *planSlot,
EPQState *epqstate,
EState *estate,
bool canSetTag)
{
Relation resultRelationDesc = resultRelInfo->ri_RelationDesc;
TM_Result result;
TM_FailureData tmfd;
List *recheckIndexes = NIL;
/*
* abort the operation if not running transactions
*/
if (IsBootstrapProcessingMode())
elog(ERROR, "cannot UPDATE during bootstrap");
ExecMaterializeSlot(slot);
/*
* Open the table's indexes, if we have not done so already, so that we
* can add new index entries for the updated tuple.
*/
if (resultRelationDesc->rd_rel->relhasindex &&
resultRelInfo->ri_IndexRelationDescs == NULL)
ExecOpenIndices(resultRelInfo, false);
/* BEFORE ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_update_before_row)
{
if (!ExecBRUpdateTriggers(estate, epqstate, resultRelInfo,
tupleid, oldtuple, slot))
return NULL; /* "do nothing" */
}
/* INSTEAD OF ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->trig_update_instead_row)
{
if (!ExecIRUpdateTriggers(estate, resultRelInfo,
oldtuple, slot))
return NULL; /* "do nothing" */
}
else if (resultRelInfo->ri_FdwRoutine)
{
/*
* Compute stored generated columns
*/
if (resultRelationDesc->rd_att->constr &&
resultRelationDesc->rd_att->constr->has_generated_stored)
ExecComputeStoredGenerated(resultRelInfo, estate, slot,
CMD_UPDATE);
/*
* update in foreign table: let the FDW do it
*/
slot = resultRelInfo->ri_FdwRoutine->ExecForeignUpdate(estate,
resultRelInfo,
slot,
planSlot);
if (slot == NULL) /* "do nothing" */
return NULL;
/*
* AFTER ROW Triggers or RETURNING expressions might reference the
* tableoid column, so (re-)initialize tts_tableOid before evaluating
* them.
*/
slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
}
else
{
LockTupleMode lockmode;
bool partition_constraint_failed;
bool update_indexes;
/*
* Constraints might reference the tableoid column, so (re-)initialize
* tts_tableOid before evaluating them.
*/
slot->tts_tableOid = RelationGetRelid(resultRelationDesc);
/*
* Compute stored generated columns
*/
if (resultRelationDesc->rd_att->constr &&
resultRelationDesc->rd_att->constr->has_generated_stored)
ExecComputeStoredGenerated(resultRelInfo, estate, slot,
CMD_UPDATE);
/*
* Check any RLS UPDATE WITH CHECK policies
*
* If we generate a new candidate tuple after EvalPlanQual testing, we
* must loop back here and recheck any RLS policies and constraints.
* (We don't need to redo triggers, however. If there are any BEFORE
* triggers then trigger.c will have done table_tuple_lock to lock the
* correct tuple, so there's no need to do them again.)
*/
lreplace:;
/* ensure slot is independent, consider e.g. EPQ */
ExecMaterializeSlot(slot);
/*
* If partition constraint fails, this row might get moved to another
* partition, in which case we should check the RLS CHECK policy just
* before inserting into the new partition, rather than doing it here.
* This is because a trigger on that partition might again change the
* row. So skip the WCO checks if the partition constraint fails.
*/
partition_constraint_failed =
resultRelationDesc->rd_rel->relispartition &&
!ExecPartitionCheck(resultRelInfo, slot, estate, false);
if (!partition_constraint_failed &&
resultRelInfo->ri_WithCheckOptions != NIL)
{
/*
* ExecWithCheckOptions() will skip any WCOs which are not of the
* kind we are looking for at this point.
*/
ExecWithCheckOptions(WCO_RLS_UPDATE_CHECK,
resultRelInfo, slot, estate);
}
/*
* If a partition check failed, try to move the row into the right
* partition.
*/
if (partition_constraint_failed)
{
TupleTableSlot *inserted_tuple,
*retry_slot;
bool retry;
/*
* ExecCrossPartitionUpdate will first DELETE the row from the
* partition it's currently in and then insert it back into the
* root table, which will re-route it to the correct partition.
* The first part may have to be repeated if it is detected that
* the tuple we're trying to move has been concurrently updated.
*/
retry = !ExecCrossPartitionUpdate(mtstate, resultRelInfo, tupleid,
oldtuple, slot, planSlot,
epqstate, canSetTag,
&retry_slot, &inserted_tuple);
if (retry)
{
slot = retry_slot;
goto lreplace;
}
return inserted_tuple;
}
/*
* Check the constraints of the tuple. We've already checked the
* partition constraint above; however, we must still ensure the tuple
* passes all other constraints, so we will call ExecConstraints() and
* have it validate all remaining checks.
*/
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 = table_tuple_update(resultRelationDesc, tupleid, slot,
estate->es_output_cid,
estate->es_snapshot,
estate->es_crosscheck_snapshot,
true /* wait for commit */ ,
&tmfd, &lockmode, &update_indexes);
switch (result)
{
case TM_SelfModified:
/*
* The target tuple was already updated or deleted by the
* current command, or by a later command in the current
* transaction. The former case is possible in a join UPDATE
* where multiple tuples join to the same target tuple. This
* is pretty questionable, but Postgres has always allowed it:
* we just execute the first update action and ignore
* additional update attempts.
*
* The latter case arises if the tuple is modified by a
* command in a BEFORE trigger, or perhaps by a command in a
* volatile function used in the query. In such situations we
* should not ignore the update, but it is equally unsafe to
* proceed. We don't want to discard the original UPDATE
* while keeping the triggered actions based on it; and we
* have no principled way to merge this update with the
* previous ones. So throwing an error is the only safe
* course.
*
* If a trigger actually intends this type of interaction, it
* can re-execute the UPDATE (assuming it can figure out how)
* and then return NULL to cancel the outer update.
*/
if (tmfd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
/* Else, already updated by self; nothing to do */
return NULL;
case TM_Ok:
break;
case TM_Updated:
{
TupleTableSlot *inputslot;
TupleTableSlot *epqslot;
TupleTableSlot *oldSlot;
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
/*
* Already know that we're going to need to do EPQ, so
* fetch tuple directly into the right slot.
*/
inputslot = EvalPlanQualSlot(epqstate, resultRelationDesc,
resultRelInfo->ri_RangeTableIndex);
result = table_tuple_lock(resultRelationDesc, tupleid,
estate->es_snapshot,
inputslot, estate->es_output_cid,
lockmode, LockWaitBlock,
TUPLE_LOCK_FLAG_FIND_LAST_VERSION,
&tmfd);
switch (result)
{
case TM_Ok:
Assert(tmfd.traversed);
epqslot = EvalPlanQual(epqstate,
resultRelationDesc,
resultRelInfo->ri_RangeTableIndex,
inputslot);
if (TupIsNull(epqslot))
/* Tuple not passing quals anymore, exiting... */
return NULL;
/* Fetch the most recent version of old tuple. */
oldSlot = resultRelInfo->ri_oldTupleSlot;
if (!table_tuple_fetch_row_version(resultRelationDesc,
tupleid,
SnapshotAny,
oldSlot))
elog(ERROR, "failed to fetch tuple being updated");
slot = ExecGetUpdateNewTuple(resultRelInfo,
epqslot, oldSlot);
goto lreplace;
case TM_Deleted:
/* tuple already deleted; nothing to do */
return NULL;
case TM_SelfModified:
/*
* This can be reached when following an update
* chain from a tuple updated by another session,
* reaching a tuple that was already updated in
* this transaction. If previously modified by
* this command, ignore the redundant update,
* otherwise error out.
*
* See also TM_SelfModified response to
* table_tuple_update() above.
*/
if (tmfd.cmax != estate->es_output_cid)
ereport(ERROR,
(errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION),
errmsg("tuple to be updated was already modified by an operation triggered by the current command"),
errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.")));
return NULL;
default:
/* see table_tuple_lock call in ExecDelete() */
elog(ERROR, "unexpected table_tuple_lock status: %u",
result);
return NULL;
}
}
break;
case TM_Deleted:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent delete")));
/* tuple already deleted; nothing to do */
return NULL;
default:
elog(ERROR, "unrecognized table_tuple_update status: %u",
result);
return NULL;
}
/* insert index entries for tuple if necessary */
if (resultRelInfo->ri_NumIndices > 0 && update_indexes)
recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
slot, estate, true, false,
NULL, NIL);
}
if (canSetTag)
(estate->es_processed)++;
/* AFTER ROW UPDATE Triggers */
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, oldtuple, slot,
recheckIndexes,
mtstate->operation == CMD_INSERT ?
mtstate->mt_oc_transition_capture :
mtstate->mt_transition_capture);
list_free(recheckIndexes);
/*
* Check any WITH CHECK OPTION constraints from parent views. We are
* required to do this after testing all constraints and uniqueness
* violations per the SQL spec, so we do it after actually updating the
* record in the heap and all indexes.
*
* ExecWithCheckOptions() will skip any WCOs which are not of the kind we
* are looking for at this point.
*/
if (resultRelInfo->ri_WithCheckOptions != NIL)
ExecWithCheckOptions(WCO_VIEW_CHECK, resultRelInfo, slot, estate);
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
return ExecProcessReturning(resultRelInfo, slot, planSlot);
return NULL;
}
/*
* ExecOnConflictUpdate --- execute UPDATE of INSERT ON CONFLICT DO UPDATE
*
* Try to lock tuple for update as part of speculative insertion. If
* a qual originating from ON CONFLICT DO UPDATE is satisfied, update
* (but still lock row, even though it may not satisfy estate's
* snapshot).
*
* Returns true if we're done (with or without an update), or false if
* the caller must retry the INSERT from scratch.
*/
static bool
ExecOnConflictUpdate(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
ItemPointer conflictTid,
TupleTableSlot *planSlot,
TupleTableSlot *excludedSlot,
EState *estate,
bool canSetTag,
TupleTableSlot **returning)
{
ExprContext *econtext = mtstate->ps.ps_ExprContext;
Relation relation = resultRelInfo->ri_RelationDesc;
ExprState *onConflictSetWhere = resultRelInfo->ri_onConflict->oc_WhereClause;
TupleTableSlot *existing = resultRelInfo->ri_onConflict->oc_Existing;
TM_FailureData tmfd;
LockTupleMode lockmode;
TM_Result test;
Datum xminDatum;
TransactionId xmin;
bool isnull;
/* Determine lock mode to use */
lockmode = ExecUpdateLockMode(estate, resultRelInfo);
/*
* Lock tuple for update. Don't follow updates when tuple cannot be
* locked without doing so. A row locking conflict here means our
* previous conclusion that the tuple is conclusively committed is not
* true anymore.
*/
test = table_tuple_lock(relation, conflictTid,
estate->es_snapshot,
existing, estate->es_output_cid,
lockmode, LockWaitBlock, 0,
&tmfd);
switch (test)
{
case TM_Ok:
/* success! */
break;
case TM_Invisible:
/*
* This can occur when a just inserted tuple is updated again in
* the same command. E.g. because multiple rows with the same
* conflicting key values are inserted.
*
* This is somewhat similar to the ExecUpdate() TM_SelfModified
* case. We do not want to proceed because it would lead to the
* same row being updated a second time in some unspecified order,
* and in contrast to plain UPDATEs there's no historical behavior
* to break.
*
* It is the user's responsibility to prevent this situation from
* occurring. These problems are why SQL-2003 similarly specifies
* that for SQL MERGE, an exception must be raised in the event of
* an attempt to update the same row twice.
*/
xminDatum = slot_getsysattr(existing,
MinTransactionIdAttributeNumber,
&isnull);
Assert(!isnull);
xmin = DatumGetTransactionId(xminDatum);
if (TransactionIdIsCurrentTransactionId(xmin))
ereport(ERROR,
(errcode(ERRCODE_CARDINALITY_VIOLATION),
errmsg("ON CONFLICT DO UPDATE command cannot affect row a second time"),
errhint("Ensure that no rows proposed for insertion within the same command have duplicate constrained values.")));
/* This shouldn't happen */
elog(ERROR, "attempted to lock invisible tuple");
break;
case TM_SelfModified:
/*
* This state should never be reached. As a dirty snapshot is used
* to find conflicting tuples, speculative insertion wouldn't have
* seen this row to conflict with.
*/
elog(ERROR, "unexpected self-updated tuple");
break;
case TM_Updated:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
/*
* As long as we don't support an UPDATE of INSERT ON CONFLICT for
* a partitioned table we shouldn't reach to a case where tuple to
* be lock is moved to another partition due to concurrent update
* of the partition key.
*/
Assert(!ItemPointerIndicatesMovedPartitions(&tmfd.ctid));
/*
* Tell caller to try again from the very start.
*
* It does not make sense to use the usual EvalPlanQual() style
* loop here, as the new version of the row might not conflict
* anymore, or the conflicting tuple has actually been deleted.
*/
ExecClearTuple(existing);
return false;
case TM_Deleted:
if (IsolationUsesXactSnapshot())
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent delete")));
/* see TM_Updated case */
Assert(!ItemPointerIndicatesMovedPartitions(&tmfd.ctid));
ExecClearTuple(existing);
return false;
default:
elog(ERROR, "unrecognized table_tuple_lock status: %u", test);
}
/* Success, the tuple is locked. */
/*
* Verify that the tuple is visible to our MVCC snapshot if the current
* isolation level mandates that.
*
* It's not sufficient to rely on the check within ExecUpdate() as e.g.
* CONFLICT ... WHERE clause may prevent us from reaching that.
*
* This means we only ever continue when a new command in the current
* transaction could see the row, even though in READ COMMITTED mode the
* tuple will not be visible according to the current statement's
* snapshot. This is in line with the way UPDATE deals with newer tuple
* versions.
*/
ExecCheckTupleVisible(estate, relation, existing);
/*
* Make tuple and any needed join variables available to ExecQual and
* ExecProject. The EXCLUDED tuple is installed in ecxt_innertuple, while
* the target's existing tuple is installed in the scantuple. EXCLUDED
* has been made to reference INNER_VAR in setrefs.c, but there is no
* other redirection.
*/
econtext->ecxt_scantuple = existing;
econtext->ecxt_innertuple = excludedSlot;
econtext->ecxt_outertuple = NULL;
if (!ExecQual(onConflictSetWhere, econtext))
{
ExecClearTuple(existing); /* see return below */
InstrCountFiltered1(&mtstate->ps, 1);
return true; /* done with the tuple */
}
if (resultRelInfo->ri_WithCheckOptions != NIL)
{
/*
* Check target's existing tuple against UPDATE-applicable USING
* security barrier quals (if any), enforced here as RLS checks/WCOs.
*
* The rewriter creates UPDATE RLS checks/WCOs for UPDATE security
* quals, and stores them as WCOs of "kind" WCO_RLS_CONFLICT_CHECK,
* but that's almost the extent of its special handling for ON
* CONFLICT DO UPDATE.
*
* The rewriter will also have associated UPDATE applicable straight
* RLS checks/WCOs for the benefit of the ExecUpdate() call that
* follows. INSERTs and UPDATEs naturally have mutually exclusive WCO
* kinds, so there is no danger of spurious over-enforcement in the
* INSERT or UPDATE path.
*/
ExecWithCheckOptions(WCO_RLS_CONFLICT_CHECK, resultRelInfo,
existing,
mtstate->ps.state);
}
/* Project the new tuple version */
ExecProject(resultRelInfo->ri_onConflict->oc_ProjInfo);
/*
* Note that it is possible that the target tuple has been modified in
* this session, after the above table_tuple_lock. We choose to not error
* out in that case, in line with ExecUpdate's treatment of similar cases.
* This can happen if an UPDATE is triggered from within ExecQual(),
* ExecWithCheckOptions() or ExecProject() above, e.g. by selecting from a
* wCTE in the ON CONFLICT's SET.
*/
/* Execute UPDATE with projection */
*returning = ExecUpdate(mtstate, resultRelInfo, conflictTid, NULL,
resultRelInfo->ri_onConflict->oc_ProjSlot,
planSlot,
&mtstate->mt_epqstate, mtstate->ps.state,
canSetTag);
/*
* Clear out existing tuple, as there might not be another conflict among
* the next input rows. Don't want to hold resources till the end of the
* query.
*/
ExecClearTuple(existing);
return true;
}
/*
* Process BEFORE EACH STATEMENT triggers
*/
static void
fireBSTriggers(ModifyTableState *node)
{
ModifyTable *plan = (ModifyTable *) node->ps.plan;
ResultRelInfo *resultRelInfo = node->rootResultRelInfo;
switch (node->operation)
{
case CMD_INSERT:
ExecBSInsertTriggers(node->ps.state, resultRelInfo);
if (plan->onConflictAction == ONCONFLICT_UPDATE)
ExecBSUpdateTriggers(node->ps.state,
resultRelInfo);
break;
case CMD_UPDATE:
ExecBSUpdateTriggers(node->ps.state, resultRelInfo);
break;
case CMD_DELETE:
ExecBSDeleteTriggers(node->ps.state, resultRelInfo);
break;
default:
elog(ERROR, "unknown operation");
break;
}
}
/*
* Process AFTER EACH STATEMENT triggers
*/
static void
fireASTriggers(ModifyTableState *node)
{
ModifyTable *plan = (ModifyTable *) node->ps.plan;
ResultRelInfo *resultRelInfo = node->rootResultRelInfo;
switch (node->operation)
{
case CMD_INSERT:
if (plan->onConflictAction == ONCONFLICT_UPDATE)
ExecASUpdateTriggers(node->ps.state,
resultRelInfo,
node->mt_oc_transition_capture);
ExecASInsertTriggers(node->ps.state, resultRelInfo,
node->mt_transition_capture);
break;
case CMD_UPDATE:
ExecASUpdateTriggers(node->ps.state, resultRelInfo,
node->mt_transition_capture);
break;
case CMD_DELETE:
ExecASDeleteTriggers(node->ps.state, resultRelInfo,
node->mt_transition_capture);
break;
default:
elog(ERROR, "unknown operation");
break;
}
}
/*
* Set up the state needed for collecting transition tuples for AFTER
* triggers.
*/
static void
ExecSetupTransitionCaptureState(ModifyTableState *mtstate, EState *estate)
{
ModifyTable *plan = (ModifyTable *) mtstate->ps.plan;
ResultRelInfo *targetRelInfo = mtstate->rootResultRelInfo;
/* Check for transition tables on the directly targeted relation. */
mtstate->mt_transition_capture =
MakeTransitionCaptureState(targetRelInfo->ri_TrigDesc,
RelationGetRelid(targetRelInfo->ri_RelationDesc),
mtstate->operation);
if (plan->operation == CMD_INSERT &&
plan->onConflictAction == ONCONFLICT_UPDATE)
mtstate->mt_oc_transition_capture =
MakeTransitionCaptureState(targetRelInfo->ri_TrigDesc,
RelationGetRelid(targetRelInfo->ri_RelationDesc),
CMD_UPDATE);
}
/*
* ExecPrepareTupleRouting --- prepare for routing one tuple
*
* Determine the partition in which the tuple in slot is to be inserted,
* and return its ResultRelInfo in *partRelInfo. The return value is
* a slot holding the tuple of the partition rowtype.
*
* This also sets the transition table information in mtstate based on the
* selected partition.
*/
static TupleTableSlot *
ExecPrepareTupleRouting(ModifyTableState *mtstate,
EState *estate,
PartitionTupleRouting *proute,
ResultRelInfo *targetRelInfo,
TupleTableSlot *slot,
ResultRelInfo **partRelInfo)
{
ResultRelInfo *partrel;
TupleConversionMap *map;
/*
* Lookup the target partition's ResultRelInfo. If ExecFindPartition does
* not find a valid partition for the tuple in 'slot' then an error is
* raised. An error may also be raised if the found partition is not a
* valid target for INSERTs. This is required since a partitioned table
* UPDATE to another partition becomes a DELETE+INSERT.
*/
partrel = ExecFindPartition(mtstate, targetRelInfo, proute, slot, estate);
/*
* If we're capturing transition tuples, we might need to convert from the
* partition rowtype to root partitioned table's rowtype. But if there
* are no BEFORE triggers on the partition that could change the tuple, we
* can just remember the original unconverted tuple to avoid a needless
* round trip conversion.
*/
if (mtstate->mt_transition_capture != NULL)
{
bool has_before_insert_row_trig;
has_before_insert_row_trig = (partrel->ri_TrigDesc &&
partrel->ri_TrigDesc->trig_insert_before_row);
mtstate->mt_transition_capture->tcs_original_insert_tuple =
!has_before_insert_row_trig ? slot : NULL;
}
/*
* Convert the tuple, if necessary.
*/
map = partrel->ri_RootToPartitionMap;
if (map != NULL)
{
TupleTableSlot *new_slot = partrel->ri_PartitionTupleSlot;
slot = execute_attr_map_slot(map->attrMap, slot, new_slot);
}
*partRelInfo = partrel;
return slot;
}
/* ----------------------------------------------------------------
* ExecModifyTable
*
* Perform table modifications as required, and return RETURNING results
* if needed.
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ExecModifyTable(PlanState *pstate)
{
ModifyTableState *node = castNode(ModifyTableState, pstate);
EState *estate = node->ps.state;
CmdType operation = node->operation;
ResultRelInfo *resultRelInfo;
PlanState *subplanstate;
TupleTableSlot *slot;
TupleTableSlot *planSlot;
TupleTableSlot *oldSlot;
ItemPointer tupleid;
ItemPointerData tuple_ctid;
HeapTupleData oldtupdata;
HeapTuple oldtuple;
PartitionTupleRouting *proute = node->mt_partition_tuple_routing;
List *relinfos = NIL;
ListCell *lc;
CHECK_FOR_INTERRUPTS();
/*
* 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. (Note:
* although ModifyTable should not get executed within an EvalPlanQual
* operation, we do have to allow it to be initialized and shut down in
* case it is within a CTE subplan. Hence this test must be here, not in
* ExecInitModifyTable.)
*/
if (estate->es_epq_active != NULL)
elog(ERROR, "ModifyTable should not be called during EvalPlanQual");
/*
* 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_lastResultIndex;
subplanstate = outerPlanState(node);
/*
* Fetch rows from subplan, 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);
/*
* Reset per-tuple memory context used for processing on conflict and
* returning clauses, to free any expression evaluation storage
* allocated in the previous cycle.
*/
if (pstate->ps_ExprContext)
ResetExprContext(pstate->ps_ExprContext);
planSlot = ExecProcNode(subplanstate);
/* No more tuples to process? */
if (TupIsNull(planSlot))
break;
/*
* When there are multiple result relations, each tuple contains a
* junk column that gives the OID of the rel from which it came.
* Extract it and select the correct result relation.
*/
if (AttributeNumberIsValid(node->mt_resultOidAttno))
{
Datum datum;
bool isNull;
Oid resultoid;
datum = ExecGetJunkAttribute(planSlot, node->mt_resultOidAttno,
&isNull);
if (isNull)
elog(ERROR, "tableoid is NULL");
resultoid = DatumGetObjectId(datum);
/* If it's not the same as last time, we need to locate the rel */
if (resultoid != node->mt_lastResultOid)
resultRelInfo = ExecLookupResultRelByOid(node, resultoid,
false, true);
}
/*
* If resultRelInfo->ri_usesFdwDirectModify is true, all we need to do
* here is compute the RETURNING expressions.
*/
if (resultRelInfo->ri_usesFdwDirectModify)
{
Assert(resultRelInfo->ri_projectReturning);
/*
* A scan slot containing the data that was actually inserted,
* updated or deleted has already been made available to
* ExecProcessReturning by IterateDirectModify, so no need to
* provide it here.
*/
slot = ExecProcessReturning(resultRelInfo, NULL, planSlot);
return slot;
}
EvalPlanQualSetSlot(&node->mt_epqstate, planSlot);
slot = planSlot;
tupleid = NULL;
oldtuple = NULL;
/*
* For UPDATE/DELETE, fetch the row identity info for the tuple to be
* updated/deleted. For a heap relation, that's a TID; otherwise we
* may have a wholerow junk attr that carries the old tuple in toto.
* Keep this in step with the part of ExecInitModifyTable that sets up
* ri_RowIdAttNo.
*/
if (operation == CMD_UPDATE || operation == CMD_DELETE)
{
char relkind;
Datum datum;
bool isNull;
relkind = resultRelInfo->ri_RelationDesc->rd_rel->relkind;
if (relkind == RELKIND_RELATION ||
relkind == RELKIND_MATVIEW ||
relkind == RELKIND_PARTITIONED_TABLE)
{
/* ri_RowIdAttNo refers to a ctid attribute */
Assert(AttributeNumberIsValid(resultRelInfo->ri_RowIdAttNo));
datum = ExecGetJunkAttribute(slot,
resultRelInfo->ri_RowIdAttNo,
&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;
}
/*
* Use the wholerow attribute, when available, to reconstruct the
* old relation tuple. The old tuple serves one or both of two
* purposes: 1) it serves as the OLD tuple for row triggers, 2) it
* provides values for any unchanged columns for the NEW tuple of
* an UPDATE, because the subplan does not produce all the columns
* of the target table.
*
* Note that the wholerow attribute does not carry system columns,
* so foreign table triggers miss seeing those, except that we
* know enough here to set t_tableOid. Quite separately from
* this, the FDW may fetch its own junk attrs to identify the row.
*
* Other relevant relkinds, currently limited to views, always
* have a wholerow attribute.
*/
else if (AttributeNumberIsValid(resultRelInfo->ri_RowIdAttNo))
{
datum = ExecGetJunkAttribute(slot,
resultRelInfo->ri_RowIdAttNo,
&isNull);
/* shouldn't ever get a null result... */
if (isNull)
elog(ERROR, "wholerow is NULL");
oldtupdata.t_data = DatumGetHeapTupleHeader(datum);
oldtupdata.t_len =
HeapTupleHeaderGetDatumLength(oldtupdata.t_data);
ItemPointerSetInvalid(&(oldtupdata.t_self));
/* Historically, view triggers see invalid t_tableOid. */
oldtupdata.t_tableOid =
(relkind == RELKIND_VIEW) ? InvalidOid :
RelationGetRelid(resultRelInfo->ri_RelationDesc);
oldtuple = &oldtupdata;
}
else
{
/* Only foreign tables are allowed to omit a row-ID attr */
Assert(relkind == RELKIND_FOREIGN_TABLE);
}
}
switch (operation)
{
case CMD_INSERT:
slot = ExecGetInsertNewTuple(resultRelInfo, planSlot);
slot = ExecInsert(node, resultRelInfo, slot, planSlot,
estate, node->canSetTag);
break;
case CMD_UPDATE:
/*
* Make the new tuple by combining plan's output tuple with
* the old tuple being updated.
*/
oldSlot = resultRelInfo->ri_oldTupleSlot;
if (oldtuple != NULL)
{
/* Use the wholerow junk attr as the old tuple. */
ExecForceStoreHeapTuple(oldtuple, oldSlot, false);
}
else
{
/* Fetch the most recent version of old tuple. */
Relation relation = resultRelInfo->ri_RelationDesc;
Assert(tupleid != NULL);
if (!table_tuple_fetch_row_version(relation, tupleid,
SnapshotAny,
oldSlot))
elog(ERROR, "failed to fetch tuple being updated");
}
slot = ExecGetUpdateNewTuple(resultRelInfo, planSlot,
oldSlot);
/* Now apply the update. */
slot = ExecUpdate(node, resultRelInfo, tupleid, oldtuple, slot,
planSlot, &node->mt_epqstate, estate,
node->canSetTag);
break;
case CMD_DELETE:
slot = ExecDelete(node, resultRelInfo, tupleid, oldtuple,
planSlot, &node->mt_epqstate, estate,
true, /* processReturning */
node->canSetTag,
false, /* changingPart */
NULL, NULL);
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)
return slot;
}
/*
* Insert remaining tuples for batch insert.
*/
if (proute)
relinfos = estate->es_tuple_routing_result_relations;
else
relinfos = estate->es_opened_result_relations;
foreach(lc, relinfos)
{
resultRelInfo = lfirst(lc);
if (resultRelInfo->ri_NumSlots > 0)
ExecBatchInsert(node, resultRelInfo,
resultRelInfo->ri_Slots,
resultRelInfo->ri_PlanSlots,
resultRelInfo->ri_NumSlots,
estate, node->canSetTag);
}
/*
* We're done, but fire AFTER STATEMENT triggers before exiting.
*/
fireASTriggers(node);
node->mt_done = true;
return NULL;
}
/*
* ExecLookupResultRelByOid
* If the table with given OID is among the result relations to be
* updated by the given ModifyTable node, return its ResultRelInfo.
*
* If not found, return NULL if missing_ok, else raise error.
*
* If update_cache is true, then upon successful lookup, update the node's
* one-element cache. ONLY ExecModifyTable may pass true for this.
*/
ResultRelInfo *
ExecLookupResultRelByOid(ModifyTableState *node, Oid resultoid,
bool missing_ok, bool update_cache)
{
if (node->mt_resultOidHash)
{
/* Use the pre-built hash table to locate the rel */
MTTargetRelLookup *mtlookup;
mtlookup = (MTTargetRelLookup *)
hash_search(node->mt_resultOidHash, &resultoid, HASH_FIND, NULL);
if (mtlookup)
{
if (update_cache)
{
node->mt_lastResultOid = resultoid;
node->mt_lastResultIndex = mtlookup->relationIndex;
}
return node->resultRelInfo + mtlookup->relationIndex;
}
}
else
{
/* With few target rels, just search the ResultRelInfo array */
for (int ndx = 0; ndx < node->mt_nrels; ndx++)
{
ResultRelInfo *rInfo = node->resultRelInfo + ndx;
if (RelationGetRelid(rInfo->ri_RelationDesc) == resultoid)
{
if (update_cache)
{
node->mt_lastResultOid = resultoid;
node->mt_lastResultIndex = ndx;
}
return rInfo;
}
}
}
if (!missing_ok)
elog(ERROR, "incorrect result relation OID %u", resultoid);
return NULL;
}
/* ----------------------------------------------------------------
* ExecInitModifyTable
* ----------------------------------------------------------------
*/
ModifyTableState *
ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
{
ModifyTableState *mtstate;
Plan *subplan = outerPlan(node);
CmdType operation = node->operation;
int nrels = list_length(node->resultRelations);
ResultRelInfo *resultRelInfo;
List *arowmarks;
ListCell *l;
int i;
Relation rel;
/* check for unsupported flags */
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
/*
* create state structure
*/
mtstate = makeNode(ModifyTableState);
mtstate->ps.plan = (Plan *) node;
mtstate->ps.state = estate;
mtstate->ps.ExecProcNode = ExecModifyTable;
mtstate->operation = operation;
mtstate->canSetTag = node->canSetTag;
mtstate->mt_done = false;
mtstate->mt_nrels = nrels;
mtstate->resultRelInfo = (ResultRelInfo *)
palloc(nrels * sizeof(ResultRelInfo));
/*----------
* Resolve the target relation. This is the same as:
*
* - the relation for which we will fire FOR STATEMENT triggers,
* - the relation into whose tuple format all captured transition tuples
* must be converted, and
* - the root partitioned table used for tuple routing.
*
* If it's a partitioned table, the root partition doesn't appear
* elsewhere in the plan and its RT index is given explicitly in
* node->rootRelation. Otherwise (i.e. table inheritance) the target
* relation is the first relation in the node->resultRelations list.
*----------
*/
if (node->rootRelation > 0)
{
mtstate->rootResultRelInfo = makeNode(ResultRelInfo);
ExecInitResultRelation(estate, mtstate->rootResultRelInfo,
node->rootRelation);
}
else
{
mtstate->rootResultRelInfo = mtstate->resultRelInfo;
ExecInitResultRelation(estate, mtstate->resultRelInfo,
linitial_int(node->resultRelations));
}
/* set up epqstate with dummy subplan data for the moment */
EvalPlanQualInit(&mtstate->mt_epqstate, estate, NULL, NIL, node->epqParam);
mtstate->fireBSTriggers = true;
/*
* Build state for collecting transition tuples. This requires having a
* valid trigger query context, so skip it in explain-only mode.
*/
if (!(eflags & EXEC_FLAG_EXPLAIN_ONLY))
ExecSetupTransitionCaptureState(mtstate, estate);
/*
* Open all the result relations and initialize the ResultRelInfo structs.
* (But root relation was initialized above, if it's part of the array.)
* We must do this before initializing the subplan, because direct-modify
* FDWs expect their ResultRelInfos to be available.
*/
resultRelInfo = mtstate->resultRelInfo;
i = 0;
foreach(l, node->resultRelations)
{
Index resultRelation = lfirst_int(l);
if (resultRelInfo != mtstate->rootResultRelInfo)
{
ExecInitResultRelation(estate, resultRelInfo, resultRelation);
/*
* For child result relations, store the root result relation
* pointer. We do so for the convenience of places that want to
* look at the query's original target relation but don't have the
* mtstate handy.
*/
resultRelInfo->ri_RootResultRelInfo = mtstate->rootResultRelInfo;
}
/* Initialize the usesFdwDirectModify flag */
resultRelInfo->ri_usesFdwDirectModify = bms_is_member(i,
node->fdwDirectModifyPlans);
/*
* Verify result relation is a valid target for the current operation
*/
CheckValidResultRel(resultRelInfo, operation);
resultRelInfo++;
i++;
}
/*
* Now we may initialize the subplan.
*/
outerPlanState(mtstate) = ExecInitNode(subplan, estate, eflags);
/*
* Do additional per-result-relation initialization.
*/
for (i = 0; i < nrels; i++)
{
resultRelInfo = &mtstate->resultRelInfo[i];
/* Let FDWs init themselves for foreign-table result rels */
if (!resultRelInfo->ri_usesFdwDirectModify &&
resultRelInfo->ri_FdwRoutine != NULL &&
resultRelInfo->ri_FdwRoutine->BeginForeignModify != NULL)
{
List *fdw_private = (List *) list_nth(node->fdwPrivLists, i);
resultRelInfo->ri_FdwRoutine->BeginForeignModify(mtstate,
resultRelInfo,
fdw_private,
i,
eflags);
}
}
/* Get the root target relation */
rel = mtstate->rootResultRelInfo->ri_RelationDesc;
/*
* Build state for tuple routing if it's a partitioned INSERT. An UPDATE
* might need this too, but only if it actually moves tuples between
* partitions; in that case setup is done by ExecCrossPartitionUpdate.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
operation == CMD_INSERT)
mtstate->mt_partition_tuple_routing =
ExecSetupPartitionTupleRouting(estate, rel);
/*
* Initialize any WITH CHECK OPTION constraints if needed.
*/
resultRelInfo = mtstate->resultRelInfo;
foreach(l, node->withCheckOptionLists)
{
List *wcoList = (List *) lfirst(l);
List *wcoExprs = NIL;
ListCell *ll;
foreach(ll, wcoList)
{
WithCheckOption *wco = (WithCheckOption *) lfirst(ll);
ExprState *wcoExpr = ExecInitQual((List *) wco->qual,
&mtstate->ps);
wcoExprs = lappend(wcoExprs, wcoExpr);
}
resultRelInfo->ri_WithCheckOptions = wcoList;
resultRelInfo->ri_WithCheckOptionExprs = wcoExprs;
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.
*/
mtstate->ps.plan->targetlist = (List *) linitial(node->returningLists);
/* Set up a slot for the output of the RETURNING projection(s) */
ExecInitResultTupleSlotTL(&mtstate->ps, &TTSOpsVirtual);
slot = mtstate->ps.ps_ResultTupleSlot;
/* Need an econtext too */
if (mtstate->ps.ps_ExprContext == NULL)
ExecAssignExprContext(estate, &mtstate->ps);
econtext = mtstate->ps.ps_ExprContext;
/*
* Build a projection for each result rel.
*/
resultRelInfo = mtstate->resultRelInfo;
foreach(l, node->returningLists)
{
List *rlist = (List *) lfirst(l);
resultRelInfo->ri_returningList = rlist;
resultRelInfo->ri_projectReturning =
ExecBuildProjectionInfo(rlist, econtext, slot, &mtstate->ps,
resultRelInfo->ri_RelationDesc->rd_att);
resultRelInfo++;
}
}
else
{
/*
* We still must construct a dummy result tuple type, because InitPlan
* expects one (maybe should change that?).
*/
mtstate->ps.plan->targetlist = NIL;
ExecInitResultTypeTL(&mtstate->ps);
mtstate->ps.ps_ExprContext = NULL;
}
/* Set the list of arbiter indexes if needed for ON CONFLICT */
resultRelInfo = mtstate->resultRelInfo;
if (node->onConflictAction != ONCONFLICT_NONE)
{
/* insert may only have one relation, inheritance is not expanded */
Assert(nrels == 1);
resultRelInfo->ri_onConflictArbiterIndexes = node->arbiterIndexes;
}
/*
* If needed, Initialize target list, projection and qual for ON CONFLICT
* DO UPDATE.
*/
if (node->onConflictAction == ONCONFLICT_UPDATE)
{
ExprContext *econtext;
TupleDesc relationDesc;
TupleDesc tupDesc;
/* already exists if created by RETURNING processing above */
if (mtstate->ps.ps_ExprContext == NULL)
ExecAssignExprContext(estate, &mtstate->ps);
econtext = mtstate->ps.ps_ExprContext;
relationDesc = resultRelInfo->ri_RelationDesc->rd_att;
/* create state for DO UPDATE SET operation */
resultRelInfo->ri_onConflict = makeNode(OnConflictSetState);
/* initialize slot for the existing tuple */
resultRelInfo->ri_onConflict->oc_Existing =
table_slot_create(resultRelInfo->ri_RelationDesc,
&mtstate->ps.state->es_tupleTable);
/*
* Create the tuple slot for the UPDATE SET projection. We want a slot
* of the table's type here, because the slot will be used to insert
* into the table, and for RETURNING processing - which may access
* system attributes.
*/
tupDesc = ExecTypeFromTL((List *) node->onConflictSet);
resultRelInfo->ri_onConflict->oc_ProjSlot =
ExecInitExtraTupleSlot(mtstate->ps.state, tupDesc,
table_slot_callbacks(resultRelInfo->ri_RelationDesc));
/* build UPDATE SET projection state */
resultRelInfo->ri_onConflict->oc_ProjInfo =
ExecBuildProjectionInfo(node->onConflictSet, econtext,
resultRelInfo->ri_onConflict->oc_ProjSlot,
&mtstate->ps,
relationDesc);
/* initialize state to evaluate the WHERE clause, if any */
if (node->onConflictWhere)
{
ExprState *qualexpr;
qualexpr = ExecInitQual((List *) node->onConflictWhere,
&mtstate->ps);
resultRelInfo->ri_onConflict->oc_WhereClause = qualexpr;
}
}
/*
* 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.
*/
arowmarks = NIL;
foreach(l, node->rowMarks)
{
PlanRowMark *rc = lfirst_node(PlanRowMark, l);
ExecRowMark *erm;
ExecAuxRowMark *aerm;
/* ignore "parent" rowmarks; they are irrelevant at runtime */
if (rc->isParent)
continue;
/* Find ExecRowMark and build ExecAuxRowMark */
erm = ExecFindRowMark(estate, rc->rti, false);
aerm = ExecBuildAuxRowMark(erm, subplan->targetlist);
arowmarks = lappend(arowmarks, aerm);
}
EvalPlanQualSetPlan(&mtstate->mt_epqstate, subplan, arowmarks);
/*
* Initialize projection(s) to create tuples suitable for result rel(s).
* INSERT queries may need a projection to filter out junk attrs in the
* tlist. UPDATE always needs a projection, because (1) there's always
* some junk attrs, and (2) we may need to merge values of not-updated
* columns from the old tuple into the final tuple. In UPDATE, the tuple
* arriving from the subplan contains only new values for the changed
* columns, plus row identity info in the junk attrs.
*
* If there are multiple result relations, each one needs its own
* projection. Note multiple rels are only possible for UPDATE/DELETE, so
* we can't be fooled by some needing a projection 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).
*/
for (i = 0; i < nrels; i++)
{
resultRelInfo = &mtstate->resultRelInfo[i];
/*
* Prepare to generate tuples suitable for the target relation.
*/
if (operation == CMD_INSERT)
{
List *insertTargetList = NIL;
bool need_projection = false;
foreach(l, subplan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (!tle->resjunk)
insertTargetList = lappend(insertTargetList, tle);
else
need_projection = true;
}
/*
* The junk-free list must produce a tuple suitable for the result
* relation.
*/
ExecCheckPlanOutput(resultRelInfo->ri_RelationDesc,
insertTargetList);
/* We'll need a slot matching the table's format. */
resultRelInfo->ri_newTupleSlot =
table_slot_create(resultRelInfo->ri_RelationDesc,
&mtstate->ps.state->es_tupleTable);
/* Build ProjectionInfo if needed (it probably isn't). */
if (need_projection)
{
TupleDesc relDesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
/* need an expression context to do the projection */
if (mtstate->ps.ps_ExprContext == NULL)
ExecAssignExprContext(estate, &mtstate->ps);
resultRelInfo->ri_projectNew =
ExecBuildProjectionInfo(insertTargetList,
mtstate->ps.ps_ExprContext,
resultRelInfo->ri_newTupleSlot,
&mtstate->ps,
relDesc);
}
}
else if (operation == CMD_UPDATE)
{
List *updateColnos;
TupleDesc relDesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
updateColnos = (List *) list_nth(node->updateColnosLists, i);
/*
* For UPDATE, we use the old tuple to fill up missing values in
* the tuple produced by the plan to get the new tuple. We need
* two slots, both matching the table's desired format.
*/
resultRelInfo->ri_oldTupleSlot =
table_slot_create(resultRelInfo->ri_RelationDesc,
&mtstate->ps.state->es_tupleTable);
resultRelInfo->ri_newTupleSlot =
table_slot_create(resultRelInfo->ri_RelationDesc,
&mtstate->ps.state->es_tupleTable);
/* need an expression context to do the projection */
if (mtstate->ps.ps_ExprContext == NULL)
ExecAssignExprContext(estate, &mtstate->ps);
resultRelInfo->ri_projectNew =
ExecBuildUpdateProjection(subplan->targetlist,
updateColnos,
relDesc,
mtstate->ps.ps_ExprContext,
resultRelInfo->ri_newTupleSlot,
&mtstate->ps);
}
/*
* For UPDATE/DELETE, find the appropriate junk attr now, either a
* 'ctid' or 'wholerow' attribute depending on relkind. For foreign
* tables, the FDW might have created additional junk attr(s), but
* those are no concern of ours.
*/
if (operation == CMD_UPDATE || operation == CMD_DELETE)
{
char relkind;
relkind = resultRelInfo->ri_RelationDesc->rd_rel->relkind;
if (relkind == RELKIND_RELATION ||
relkind == RELKIND_MATVIEW ||
relkind == RELKIND_PARTITIONED_TABLE)
{
resultRelInfo->ri_RowIdAttNo =
ExecFindJunkAttributeInTlist(subplan->targetlist, "ctid");
if (!AttributeNumberIsValid(resultRelInfo->ri_RowIdAttNo))
elog(ERROR, "could not find junk ctid column");
}
else if (relkind == RELKIND_FOREIGN_TABLE)
{
/*
* When there is a row-level trigger, there should be a
* wholerow attribute. We also require it to be present in
* UPDATE, so we can get the values of unchanged columns.
*/
resultRelInfo->ri_RowIdAttNo =
ExecFindJunkAttributeInTlist(subplan->targetlist,
"wholerow");
if (mtstate->operation == CMD_UPDATE &&
!AttributeNumberIsValid(resultRelInfo->ri_RowIdAttNo))
elog(ERROR, "could not find junk wholerow column");
}
else
{
/* Other valid target relkinds must provide wholerow */
resultRelInfo->ri_RowIdAttNo =
ExecFindJunkAttributeInTlist(subplan->targetlist,
"wholerow");
if (!AttributeNumberIsValid(resultRelInfo->ri_RowIdAttNo))
elog(ERROR, "could not find junk wholerow column");
}
}
}
/*
* If this is an inherited update/delete, there will be a junk attribute
* named "tableoid" present in the subplan's targetlist. It will be used
* to identify the result relation for a given tuple to be
* updated/deleted.
*/
mtstate->mt_resultOidAttno =
ExecFindJunkAttributeInTlist(subplan->targetlist, "tableoid");
Assert(AttributeNumberIsValid(mtstate->mt_resultOidAttno) || nrels == 1);
mtstate->mt_lastResultOid = InvalidOid; /* force lookup at first tuple */
mtstate->mt_lastResultIndex = 0; /* must be zero if no such attr */
/*
* If there are a lot of result relations, use a hash table to speed the
* lookups. If there are not a lot, a simple linear search is faster.
*
* It's not clear where the threshold is, but try 64 for starters. In a
* debugging build, use a small threshold so that we get some test
* coverage of both code paths.
*/
#ifdef USE_ASSERT_CHECKING
#define MT_NRELS_HASH 4
#else
#define MT_NRELS_HASH 64
#endif
if (nrels >= MT_NRELS_HASH)
{
HASHCTL hash_ctl;
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(MTTargetRelLookup);
hash_ctl.hcxt = CurrentMemoryContext;
mtstate->mt_resultOidHash =
hash_create("ModifyTable target hash",
nrels, &hash_ctl,
HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
for (i = 0; i < nrels; i++)
{
Oid hashkey;
MTTargetRelLookup *mtlookup;
bool found;
resultRelInfo = &mtstate->resultRelInfo[i];
hashkey = RelationGetRelid(resultRelInfo->ri_RelationDesc);
mtlookup = (MTTargetRelLookup *)
hash_search(mtstate->mt_resultOidHash, &hashkey,
HASH_ENTER, &found);
Assert(!found);
mtlookup->relationIndex = i;
}
}
else
mtstate->mt_resultOidHash = NULL;
/*
* Determine if the FDW supports batch insert and determine the batch
* size (a FDW may support batching, but it may be disabled for the
* server/table).
*
* We only do this for INSERT, so that for UPDATE/DELETE the batch
* size remains set to 0.
*/
if (operation == CMD_INSERT)
{
/* insert may only have one relation, inheritance is not expanded */
Assert(nrels == 1);
resultRelInfo = mtstate->resultRelInfo;
if (!resultRelInfo->ri_usesFdwDirectModify &&
resultRelInfo->ri_FdwRoutine != NULL &&
resultRelInfo->ri_FdwRoutine->GetForeignModifyBatchSize &&
resultRelInfo->ri_FdwRoutine->ExecForeignBatchInsert)
{
resultRelInfo->ri_BatchSize =
resultRelInfo->ri_FdwRoutine->GetForeignModifyBatchSize(resultRelInfo);
Assert(resultRelInfo->ri_BatchSize >= 1);
}
else
resultRelInfo->ri_BatchSize = 1;
}
/*
* 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;
/*
* Allow any FDWs to shut down
*/
for (i = 0; i < node->mt_nrels; i++)
{
ResultRelInfo *resultRelInfo = node->resultRelInfo + i;
if (!resultRelInfo->ri_usesFdwDirectModify &&
resultRelInfo->ri_FdwRoutine != NULL &&
resultRelInfo->ri_FdwRoutine->EndForeignModify != NULL)
resultRelInfo->ri_FdwRoutine->EndForeignModify(node->ps.state,
resultRelInfo);
}
/*
* Close all the partitioned tables, leaf partitions, and their indices
* and release the slot used for tuple routing, if set.
*/
if (node->mt_partition_tuple_routing)
{
ExecCleanupTupleRouting(node, node->mt_partition_tuple_routing);
if (node->mt_root_tuple_slot)
ExecDropSingleTupleTableSlot(node->mt_root_tuple_slot);
}
/*
* Free the exprcontext
*/
ExecFreeExprContext(&node->ps);
/*
* clean out the tuple table
*/
if (node->ps.ps_ResultTupleSlot)
ExecClearTuple(node->ps.ps_ResultTupleSlot);
/*
* Terminate EPQ execution if active
*/
EvalPlanQualEnd(&node->mt_epqstate);
/*
* shut down subplan
*/
ExecEndNode(outerPlanState(node));
}
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");
}
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