/* ----------------------------------------------------------------
* ExecDelete
*
* DELETE is like UPDATE, except that we delete the tuple and no
* index modifications are needed.
* DELETE can be part of an update operation when
* there is a preceding SplitUpdate node.
*
* ----------------------------------------------------------------
*/
void
ExecDelete(ItemPointer tupleid,
TupleTableSlot *planSlot,
DestReceiver *dest,
EState *estate,
PlanGenerator planGen,
bool isUpdate)
{
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
HTSU_Result result;
ItemPointerData update_ctid;
TransactionId update_xmax;
/*
* Get information on the (current) result relation.
*/
if (estate->es_result_partitions && planGen == PLANGEN_OPTIMIZER)
{
Assert(estate->es_result_partitions->part->parrelid);
#ifdef USE_ASSERT_CHECKING
Oid parent = estate->es_result_partitions->part->parrelid;
#endif
/* Obtain part for current tuple. */
resultRelInfo = slot_get_partition(planSlot, estate);
estate->es_result_relation_info = resultRelInfo;
#ifdef USE_ASSERT_CHECKING
Oid part = RelationGetRelid(resultRelInfo->ri_RelationDesc);
#endif
Assert(parent != part);
}
else
{
resultRelInfo = estate->es_result_relation_info;
}
resultRelationDesc = resultRelInfo->ri_RelationDesc;
Assert (!resultRelInfo->ri_projectReturning);
if (planGen == PLANGEN_PLANNER)
{
/* BEFORE ROW DELETE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_DELETE] > 0)
{
bool dodelete;
dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
estate->es_snapshot->curcid);
if (!dodelete) /* "do nothing" */
return;
}
}
/*
* delete the tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
* the row to be deleted is visible to that snapshot, and throw a can't-
* serialize error if not. This is a special-case behavior needed for
* referential integrity updates in serializable transactions.
*/
ldelete:;
result = heap_delete(resultRelationDesc, tupleid,
&update_ctid, &update_xmax,
estate->es_snapshot->curcid,
estate->es_crosscheck_snapshot,
true /* wait for commit */ );
switch (result)
{
case HeapTupleSelfUpdated:
/* already deleted by self; nothing to do */
/*
* In an scenario in which R(a,b) and S(a,b) have
* R S
* ________ ________
* (1, 1) (1, 2)
* (1, 7)
*
* An update query such as:
* UPDATE R SET a = S.b FROM S WHERE R.b = S.a;
*
* will have an non-deterministic output. The tuple in R
* can be updated to (2,1) or (7,1).
* Since the introduction of SplitUpdate, these queries will
* send multiple requests to delete the same tuple. Therefore,
* in order to avoid a non-deterministic output,
* an error is reported in such scenario.
*/
if (isUpdate)
{
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION ),
errmsg("multiple updates to a row by the same query is not allowed")));
}
return;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
if (IsXactIsoLevelSerializable)
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
else if (!ItemPointerEquals(tupleid, &update_ctid))
{
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
resultRelInfo->ri_RangeTableIndex,
&update_ctid,
update_xmax,
estate->es_snapshot->curcid);
if (!TupIsNull(epqslot))
{
*tupleid = update_ctid;
goto ldelete;
}
}
/* tuple already deleted; nothing to do */
return;
default:
elog(ERROR, "unrecognized heap_delete status: %u", result);
return;
}
if (!isUpdate)
{
IncrDeleted();
(estate->es_processed)++;
}
/*
* Note: Normally one would think that we have to delete index tuples
* associated with the heap tuple now...
*
* ... but in POSTGRES, we have no need to do this because VACUUM will
* take care of it later. We can't delete index tuples immediately
* anyway, since the tuple is still visible to other transactions.
*/
if (planGen == PLANGEN_PLANNER)
{
/* AFTER ROW DELETE Triggers */
ExecARDeleteTriggers(estate, resultRelInfo, tupleid);
}
}
/* ----------------------------------------------------------------
* 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..
* ----------------------------------------------------------------
*/
void
ExecUpdate(TupleTableSlot *slot,
ItemPointer tupleid,
TupleTableSlot *planSlot,
DestReceiver *dest,
EState *estate)
{
HeapTuple tuple;
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
HTSU_Result result;
ItemPointerData update_ctid;
TransactionId update_xmax;
/*
* abort the operation if not running transactions
*/
if (IsBootstrapProcessingMode())
elog(ERROR, "cannot UPDATE during bootstrap");
/*
* get the heap tuple out of the tuple table slot, making sure we have a
* writable copy
*/
tuple = ExecFetchSlotHeapTuple(slot);
/*
* get information on the (current) result relation
*/
resultRelInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelInfo->ri_RelationDesc;
/* see if this update would move the tuple to a different partition */
if (estate->es_result_partitions)
{
AttrNumber max_attr;
Datum *values;
bool *nulls;
Oid targetid;
Assert(estate->es_partition_state != NULL &&
estate->es_partition_state->accessMethods != NULL);
if (!estate->es_partition_state->accessMethods->part_cxt)
estate->es_partition_state->accessMethods->part_cxt =
GetPerTupleExprContext(estate)->ecxt_per_tuple_memory;
Assert(PointerIsValid(estate->es_result_partitions));
max_attr = estate->es_partition_state->max_partition_attr;
slot_getsomeattrs(slot, max_attr);
values = slot_get_values(slot);
nulls = slot_get_isnull(slot);
targetid = selectPartition(estate->es_result_partitions, values,
nulls, slot->tts_tupleDescriptor,
estate->es_partition_state->accessMethods);
if (!OidIsValid(targetid))
ereport(ERROR,
(errcode(ERRCODE_NO_PARTITION_FOR_PARTITIONING_KEY),
errmsg("no partition for partitioning key")));
if (RelationGetRelid(resultRelationDesc) != targetid)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("moving tuple from partition \"%s\" to "
"partition \"%s\" not supported",
get_rel_name(RelationGetRelid(resultRelationDesc)),
get_rel_name(targetid)),
errOmitLocation(true)));
}
}
/* BEFORE ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
{
HeapTuple newtuple;
newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
tupleid, tuple,
estate->es_snapshot->curcid);
if (newtuple == NULL) /* "do nothing" */
return;
if (newtuple != tuple) /* modified by Trigger(s) */
{
/*
* Put the modified tuple into a slot for convenience of routines
* below. We assume the tuple was allocated in per-tuple memory
* context, and therefore will go away by itself. The tuple table
* slot should not try to clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
if (newslot->tts_tupleDescriptor != slot->tts_tupleDescriptor)
ExecSetSlotDescriptor(newslot, slot->tts_tupleDescriptor);
ExecStoreGenericTuple(newtuple, newslot, false);
newslot->tts_tableOid = slot->tts_tableOid; /* for constraints */
slot = newslot;
tuple = newtuple;
}
}
/*
* Check the constraints of the tuple
*
* If we generate a new candidate tuple after EvalPlanQual testing, we
* must loop back here and recheck constraints. (We don't need to redo
* triggers, however. If there are any BEFORE triggers then trigger.c
* will have done heap_lock_tuple to lock the correct tuple, so there's no
* need to do them again.)
*/
lreplace:;
if (resultRelationDesc->rd_att->constr)
ExecConstraints(resultRelInfo, slot, estate);
if (!GpPersistent_IsPersistentRelation(resultRelationDesc->rd_id))
{
/*
* Normal UPDATE path.
*/
/*
* replace the heap tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
* the row to be updated is visible to that snapshot, and throw a can't-
* serialize error if not. This is a special-case behavior needed for
* referential integrity updates in serializable transactions.
*/
result = heap_update(resultRelationDesc, tupleid, tuple,
&update_ctid, &update_xmax,
estate->es_snapshot->curcid,
estate->es_crosscheck_snapshot,
true /* wait for commit */ );
switch (result)
{
case HeapTupleSelfUpdated:
/* already deleted by self; nothing to do */
return;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
if (IsXactIsoLevelSerializable)
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
else if (!ItemPointerEquals(tupleid, &update_ctid))
{
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
resultRelInfo->ri_RangeTableIndex,
&update_ctid,
update_xmax,
estate->es_snapshot->curcid);
if (!TupIsNull(epqslot))
{
*tupleid = update_ctid;
slot = ExecFilterJunk(estate->es_junkFilter, epqslot);
tuple = ExecFetchSlotHeapTuple(slot);
goto lreplace;
}
}
/* tuple already deleted; nothing to do */
return;
default:
elog(ERROR, "unrecognized heap_update status: %u", result);
return;
}
}
else
{
HeapTuple persistentTuple;
/*
* Persistent metadata path.
*/
persistentTuple = heap_copytuple(tuple);
persistentTuple->t_self = *tupleid;
frozen_heap_inplace_update(resultRelationDesc, persistentTuple);
heap_freetuple(persistentTuple);
}
IncrReplaced();
(estate->es_processed)++;
/*
* Note: instead of having to update the old index tuples associated with
* the heap tuple, all we do is form and insert new index tuples. This is
* because UPDATEs are actually DELETEs and INSERTs, and index tuple
* deletion is done later by VACUUM (see notes in ExecDelete). All we do
* here is insert new index tuples. -cim 9/27/89
*/
/*
* insert index entries for tuple
*
* Note: heap_update returns the tid (location) of the new tuple in the
* t_self field.
*/
if (resultRelInfo->ri_NumIndices > 0)
ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false);
/* AFTER ROW UPDATE Triggers */
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
}
/* ----------------------------------------------------------------
* 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..
* ----------------------------------------------------------------
*/
void
ExecUpdate(TupleTableSlot *slot,
ItemPointer tupleid,
TupleTableSlot *planSlot,
DestReceiver *dest,
EState *estate)
{
void* tuple;
ResultRelInfo *resultRelInfo;
Relation resultRelationDesc;
HTSU_Result result;
ItemPointerData update_ctid;
TransactionId update_xmax;
AOTupleId aoTupleId = AOTUPLEID_INIT;
TupleTableSlot *partslot = NULL;
/*
* abort the operation if not running transactions
*/
if (IsBootstrapProcessingMode())
elog(ERROR, "cannot UPDATE during bootstrap");
/*
* get information on the (current) result relation
*/
resultRelInfo = estate->es_result_relation_info;
resultRelationDesc = resultRelInfo->ri_RelationDesc;
bool rel_is_heap = RelationIsHeap(resultRelationDesc);
bool rel_is_aorows = RelationIsAoRows(resultRelationDesc);
bool rel_is_aocols = RelationIsAoCols(resultRelationDesc);
bool rel_is_external = RelationIsExternal(resultRelationDesc);
/*
* get the heap tuple out of the tuple table slot, making sure we have a
* writable copy
*/
if (rel_is_heap)
{
partslot = slot;
tuple = ExecFetchSlotHeapTuple(partslot);
}
else if (rel_is_aorows || rel_is_aocols)
{
/*
* It is necessary to reconstruct a logically compatible tuple to
* a phyiscally compatible tuple. The slot's tuple descriptor comes
* from the projection target list, which doesn't indicate dropped
* columns, and MemTuple cannot deal with cases without converting
* the target list back into the original relation's tuple desc.
*/
partslot = reconstructMatchingTupleSlot(slot, resultRelInfo);
/*
* We directly inline toasted columns here as update with toasted columns
* would create two references to the same toasted value.
*/
tuple = ExecFetchSlotMemTuple(partslot, true);
}
else if (rel_is_external)
{
if (estate->es_result_partitions &&
estate->es_result_partitions->part->parrelid != 0)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Update external partitions not supported.")));
return;
}
else
{
partslot = slot;
tuple = ExecFetchSlotHeapTuple(partslot);
}
}
else
{
Insist(false);
}
/* see if this update would move the tuple to a different partition */
if (estate->es_result_partitions)
checkPartitionUpdate(estate, partslot, resultRelInfo);
/* BEFORE ROW UPDATE Triggers */
if (resultRelInfo->ri_TrigDesc &&
resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0)
{
HeapTuple newtuple;
newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
tupleid, tuple,
estate->es_snapshot->curcid);
if (newtuple == NULL) /* "do nothing" */
return;
if (newtuple != tuple) /* modified by Trigger(s) */
{
/*
* Put the modified tuple into a slot for convenience of routines
* below. We assume the tuple was allocated in per-tuple memory
* context, and therefore will go away by itself. The tuple table
* slot should not try to clear it.
*/
TupleTableSlot *newslot = estate->es_trig_tuple_slot;
if (newslot->tts_tupleDescriptor != partslot->tts_tupleDescriptor)
ExecSetSlotDescriptor(newslot, partslot->tts_tupleDescriptor);
ExecStoreGenericTuple(newtuple, newslot, false);
newslot->tts_tableOid = partslot->tts_tableOid; /* for constraints */
partslot = newslot;
tuple = newtuple;
}
}
/*
* Check the constraints of the tuple
*
* If we generate a new candidate tuple after EvalPlanQual testing, we
* must loop back here and recheck constraints. (We don't need to redo
* triggers, however. If there are any BEFORE triggers then trigger.c
* will have done heap_lock_tuple to lock the correct tuple, so there's no
* need to do them again.)
*/
lreplace:;
if (resultRelationDesc->rd_att->constr)
ExecConstraints(resultRelInfo, partslot, estate);
if (!GpPersistent_IsPersistentRelation(resultRelationDesc->rd_id))
{
/*
* Normal UPDATE path.
*/
/*
* replace the heap tuple
*
* Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check that
* the row to be updated is visible to that snapshot, and throw a can't-
* serialize error if not. This is a special-case behavior needed for
* referential integrity updates in serializable transactions.
*/
if (rel_is_heap)
{
result = heap_update(resultRelationDesc, tupleid, tuple,
&update_ctid, &update_xmax,
estate->es_snapshot->curcid,
estate->es_crosscheck_snapshot,
true /* wait for commit */ );
}
else if (rel_is_aorows)
{
if (IsXactIsoLevelSerializable)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Updates on append-only tables are not supported in serializable transactions.")));
}
if (resultRelInfo->ri_updateDesc == NULL)
{
ResultRelInfoSetSegno(resultRelInfo, estate->es_result_aosegnos);
resultRelInfo->ri_updateDesc = (AppendOnlyUpdateDesc)
appendonly_update_init(resultRelationDesc, ActiveSnapshot, resultRelInfo->ri_aosegno);
}
result = appendonly_update(resultRelInfo->ri_updateDesc,
tuple, (AOTupleId *) tupleid, &aoTupleId);
}
else if (rel_is_aocols)
{
if (IsXactIsoLevelSerializable)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Updates on append-only tables are not supported in serializable transactions.")));
}
if (resultRelInfo->ri_updateDesc == NULL)
{
ResultRelInfoSetSegno(resultRelInfo, estate->es_result_aosegnos);
resultRelInfo->ri_updateDesc = (AppendOnlyUpdateDesc)
aocs_update_init(resultRelationDesc, resultRelInfo->ri_aosegno);
}
result = aocs_update(resultRelInfo->ri_updateDesc,
partslot, (AOTupleId *) tupleid, &aoTupleId);
}
else
{
Assert(!"We should not be here");
}
switch (result)
{
case HeapTupleSelfUpdated:
/* already deleted by self; nothing to do */
return;
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
if (IsXactIsoLevelSerializable)
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
else if (!ItemPointerEquals(tupleid, &update_ctid))
{
TupleTableSlot *epqslot;
epqslot = EvalPlanQual(estate,
resultRelInfo->ri_RangeTableIndex,
&update_ctid,
update_xmax,
estate->es_snapshot->curcid);
if (!TupIsNull(epqslot))
{
*tupleid = update_ctid;
partslot = ExecFilterJunk(estate->es_junkFilter, epqslot);
tuple = ExecFetchSlotHeapTuple(partslot);
goto lreplace;
}
}
/* tuple already deleted; nothing to do */
return;
default:
elog(ERROR, "unrecognized heap_update status: %u", result);
return;
}
}
else
{
HeapTuple persistentTuple;
/*
* Persistent metadata path.
*/
persistentTuple = heap_copytuple(tuple);
persistentTuple->t_self = *tupleid;
frozen_heap_inplace_update(resultRelationDesc, persistentTuple);
heap_freetuple(persistentTuple);
}
IncrReplaced();
(estate->es_processed)++;
(resultRelInfo->ri_aoprocessed)++;
/*
* 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 (rel_is_aorows || rel_is_aocols)
{
if (resultRelInfo->ri_NumIndices > 0)
ExecInsertIndexTuples(partslot, (ItemPointer)&aoTupleId, estate, false);
}
else
{
if (resultRelInfo->ri_NumIndices > 0)
ExecInsertIndexTuples(partslot, &(((HeapTuple) tuple)->t_self), estate, false);
}
/* AFTER ROW UPDATE Triggers */
ExecARUpdateTriggers(estate, resultRelInfo, tupleid, tuple);
}