/* ----------------------------------------------------------------
* 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);
}
/*
* Check if the tuple being updated will stay in the same part and throw ERROR
* if not. This check is especially necessary for default partition that has
* no constraint on it. partslot is the tuple being updated, and
* resultRelInfo is the target relation of this update. Call this only
* estate has valid es_result_partitions.
*/
static void
checkPartitionUpdate(EState *estate, TupleTableSlot *partslot,
ResultRelInfo *resultRelInfo)
{
Relation resultRelationDesc = resultRelInfo->ri_RelationDesc;
AttrNumber max_attr;
Datum *values = NULL;
bool *nulls = NULL;
TupleDesc tupdesc = NULL;
Oid parentRelid;
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));
/*
* As opposed to INSERT, resultRelation here is the same child part
* as scan origin. However, the partition selection is done with the
* parent partition's attribute numbers, so if this result (child) part
* has physically-different attribute numbers due to dropped columns,
* we should map the child attribute numbers to the parent's attribute
* numbers to perform the partition selection.
* EState doesn't have the parent relation information at the moment,
* so we have to do a hard job here by opening it and compare the
* tuple descriptors. If we find we need to map attribute numbers,
* max_partition_attr could also be bogus for this child part,
* so we end up materializing the whole columns using slot_getallattrs().
* The purpose of this code is just to prevent the tuple from
* incorrectly staying in default partition that has no constraint
* (parts with constraint will throw an error if the tuple is changing
* partition keys to out of part value anyway.) It's a bit overkill
* to do this complicated logic just for this purpose, which is necessary
* with our current partitioning design, but I hope some day we can
* change this so that we disallow phyisically-different tuple descriptor
* across partition.
*/
parentRelid = estate->es_result_partitions->part->parrelid;
/*
* I don't believe this is the case currently, but we check the parent relid
* in case the updating partition has changed since the last time we opened it.
*/
if (resultRelInfo->ri_PartitionParent &&
parentRelid != RelationGetRelid(resultRelInfo->ri_PartitionParent))
{
resultRelInfo->ri_PartCheckTupDescMatch = 0;
if (resultRelInfo->ri_PartCheckMap != NULL)
pfree(resultRelInfo->ri_PartCheckMap);
if (resultRelInfo->ri_PartitionParent)
relation_close(resultRelInfo->ri_PartitionParent, AccessShareLock);
}
/*
* Check this at the first pass only to avoid repeated catalog access.
*/
if (resultRelInfo->ri_PartCheckTupDescMatch == 0 &&
parentRelid != RelationGetRelid(resultRelInfo->ri_RelationDesc))
{
Relation parentRel;
TupleDesc resultTupdesc, parentTupdesc;
/*
* We are on a child part, let's see the tuple descriptor looks like
* the parent's one. Probably this won't cause deadlock because
* DML should have opened the parent table with appropriate lock.
*/
parentRel = relation_open(parentRelid, AccessShareLock);
resultTupdesc = RelationGetDescr(resultRelationDesc);
parentTupdesc = RelationGetDescr(parentRel);
if (!equalTupleDescs(resultTupdesc, parentTupdesc, false))
{
AttrMap *map;
MemoryContext oldcontext;
/* Tuple looks different. Construct attribute mapping. */
oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
map_part_attrs(resultRelationDesc, parentRel, &map, true);
MemoryContextSwitchTo(oldcontext);
/* And save it for later use. */
resultRelInfo->ri_PartCheckMap = map;
resultRelInfo->ri_PartCheckTupDescMatch = -1;
}
else
resultRelInfo->ri_PartCheckTupDescMatch = 1;
resultRelInfo->ri_PartitionParent = parentRel;
/* parentRel will be closed as part of ResultRelInfo cleanup */
}
if (resultRelInfo->ri_PartCheckMap != NULL)
{
Datum *parent_values;
bool *parent_nulls;
Relation parentRel = resultRelInfo->ri_PartitionParent;
TupleDesc parentTupdesc;
AttrMap *map;
Assert(parentRel != NULL);
parentTupdesc = RelationGetDescr(parentRel);
/*
* We need to map the attribute numbers to parent's one, to
* select the would-be destination relation, since all partition
* rules are based on the parent relation's tuple descriptor.
* max_partition_attr can be bogus as well, so don't use it.
*/
slot_getallattrs(partslot);
values = slot_get_values(partslot);
nulls = slot_get_isnull(partslot);
parent_values = palloc(parentTupdesc->natts * sizeof(Datum));
parent_nulls = palloc0(parentTupdesc->natts * sizeof(bool));
map = resultRelInfo->ri_PartCheckMap;
reconstructTupleValues(map, values, nulls, partslot->tts_tupleDescriptor->natts,
parent_values, parent_nulls, parentTupdesc->natts);
/* Now we have values/nulls in parent's view. */
values = parent_values;
nulls = parent_nulls;
tupdesc = RelationGetDescr(parentRel);
}
else
{
/*
* map == NULL means we can just fetch values/nulls from the
* current slot.
*/
Assert(nulls == NULL && tupdesc == NULL);
max_attr = estate->es_partition_state->max_partition_attr;
slot_getsomeattrs(partslot, max_attr);
/* values/nulls pointing to partslot's array. */
values = slot_get_values(partslot);
nulls = slot_get_isnull(partslot);
tupdesc = partslot->tts_tupleDescriptor;
}
/* And select the destination relation that this tuple would go to. */
targetid = selectPartition(estate->es_result_partitions, values,
nulls, tupdesc,
estate->es_partition_state->accessMethods);
/* Free up if we allocated mapped attributes. */
if (values != slot_get_values(partslot))
{
Assert(nulls != slot_get_isnull(partslot));
pfree(values);
pfree(nulls);
}
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))));
}