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Diffstat (limited to 'src/backend/commands/tablecmds.c')
-rw-r--r--src/backend/commands/tablecmds.c59
1 files changed, 34 insertions, 25 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ea1c309add8..6a7aa44ccc6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -2741,7 +2741,7 @@ AlterTableGetLockLevel(List *cmds)
* multiple DDL operations occur in a stream against frequently accessed
* tables.
*
- * 1. Catalog tables are read using SnapshotNow, which has a race bug that
+ * 1. Catalog tables were read using SnapshotNow, which has a race bug that
* allows a scan to return no valid rows even when one is present in the
* case of a commit of a concurrent update of the catalog table.
* SnapshotNow also ignores transactions in progress, so takes the latest
@@ -3753,6 +3753,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
MemoryContext oldCxt;
List *dropped_attrs = NIL;
ListCell *lc;
+ Snapshot snapshot;
if (newrel)
ereport(DEBUG1,
@@ -3805,7 +3806,8 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
* Scan through the rows, generating a new row if needed and then
* checking all the constraints.
*/
- scan = heap_beginscan(oldrel, SnapshotNow, 0, NULL);
+ snapshot = RegisterSnapshot(GetLatestSnapshot());
+ scan = heap_beginscan(oldrel, snapshot, 0, NULL);
/*
* Switch to per-tuple memory context and reset it for each tuple
@@ -3906,6 +3908,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
MemoryContextSwitchTo(oldCxt);
heap_endscan(scan);
+ UnregisterSnapshot(snapshot);
ExecDropSingleTupleTableSlot(oldslot);
ExecDropSingleTupleTableSlot(newslot);
@@ -4182,7 +4185,7 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
ObjectIdGetDatum(typeOid));
depScan = systable_beginscan(depRel, DependReferenceIndexId, true,
- SnapshotNow, 2, key);
+ NULL, 2, key);
while (HeapTupleIsValid(depTup = systable_getnext(depScan)))
{
@@ -4281,7 +4284,7 @@ find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior be
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(typeOid));
- scan = heap_beginscan(classRel, SnapshotNow, 1, key);
+ scan = heap_beginscan_catalog(classRel, 1, key);
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
@@ -6220,7 +6223,7 @@ ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(conrel, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
while (HeapTupleIsValid(contuple = systable_getnext(scan)))
{
@@ -6282,7 +6285,7 @@ ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
ObjectIdGetDatum(HeapTupleGetOid(contuple)));
tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
- SnapshotNow, 1, &tgkey);
+ NULL, 1, &tgkey);
while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
{
@@ -6343,7 +6346,7 @@ ATExecValidateConstraint(Relation rel, char *constrName, bool recurse,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(conrel, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
@@ -6824,6 +6827,7 @@ validateCheckConstraint(Relation rel, HeapTuple constrtup)
TupleTableSlot *slot;
Form_pg_constraint constrForm;
bool isnull;
+ Snapshot snapshot;
constrForm = (Form_pg_constraint) GETSTRUCT(constrtup);
@@ -6849,7 +6853,8 @@ validateCheckConstraint(Relation rel, HeapTuple constrtup)
slot = MakeSingleTupleTableSlot(tupdesc);
econtext->ecxt_scantuple = slot;
- scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
+ snapshot = RegisterSnapshot(GetLatestSnapshot());
+ scan = heap_beginscan(rel, snapshot, 0, NULL);
/*
* Switch to per-tuple memory context and reset it for each tuple
@@ -6873,6 +6878,7 @@ validateCheckConstraint(Relation rel, HeapTuple constrtup)
MemoryContextSwitchTo(oldcxt);
heap_endscan(scan);
+ UnregisterSnapshot(snapshot);
ExecDropSingleTupleTableSlot(slot);
FreeExecutorState(estate);
}
@@ -6893,6 +6899,7 @@ validateForeignKeyConstraint(char *conname,
HeapScanDesc scan;
HeapTuple tuple;
Trigger trig;
+ Snapshot snapshot;
ereport(DEBUG1,
(errmsg("validating foreign key constraint \"%s\"", conname)));
@@ -6924,7 +6931,8 @@ validateForeignKeyConstraint(char *conname,
* if that tuple had just been inserted. If any of those fail, it should
* ereport(ERROR) and that's that.
*/
- scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
+ snapshot = RegisterSnapshot(GetLatestSnapshot());
+ scan = heap_beginscan(rel, snapshot, 0, NULL);
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
@@ -6956,6 +6964,7 @@ validateForeignKeyConstraint(char *conname,
}
heap_endscan(scan);
+ UnregisterSnapshot(snapshot);
}
static void
@@ -7174,7 +7183,7 @@ ATExecDropConstraint(Relation rel, const char *constrName,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(conrel, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
@@ -7255,7 +7264,7 @@ ATExecDropConstraint(Relation rel, const char *constrName,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(childrelid));
scan = systable_beginscan(conrel, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
/* scan for matching tuple - there should only be one */
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
@@ -7655,7 +7664,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
Int32GetDatum((int32) attnum));
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
- SnapshotNow, 3, key);
+ NULL, 3, key);
while (HeapTupleIsValid(depTup = systable_getnext(scan)))
{
@@ -7840,7 +7849,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
Int32GetDatum((int32) attnum));
scan = systable_beginscan(depRel, DependDependerIndexId, true,
- SnapshotNow, 3, key);
+ NULL, 3, key);
while (HeapTupleIsValid(depTup = systable_getnext(scan)))
{
@@ -8517,7 +8526,7 @@ change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relationOid));
scan = systable_beginscan(attRelation, AttributeRelidNumIndexId,
- true, SnapshotNow, 1, key);
+ true, NULL, 1, key);
while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
{
Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
@@ -8594,7 +8603,7 @@ change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lock
/* we leave refobjsubid unspecified */
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
- SnapshotNow, 2, key);
+ NULL, 2, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
@@ -9188,7 +9197,7 @@ ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
/* inhseqno sequences start at 1 */
inhseqno = 0;
@@ -9430,7 +9439,7 @@ MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(parent_rel)));
parent_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &parent_key);
+ true, NULL, 1, &parent_key);
while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan)))
{
@@ -9453,7 +9462,7 @@ MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
child_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId,
- true, SnapshotNow, 1, &child_key);
+ true, NULL, 1, &child_key);
while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan)))
{
@@ -9561,7 +9570,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
- true, SnapshotNow, 1, key);
+ true, NULL, 1, key);
while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
{
@@ -9595,7 +9604,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId,
- true, SnapshotNow, 1, key);
+ true, NULL, 1, key);
while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
{
Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
@@ -9637,7 +9646,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(parent_rel)));
scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId,
- true, SnapshotNow, 1, key);
+ true, NULL, 1, key);
connames = NIL;
@@ -9657,7 +9666,7 @@ ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId,
- true, SnapshotNow, 1, key);
+ true, NULL, 1, key);
while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
{
@@ -9749,7 +9758,7 @@ drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid)
Int32GetDatum(0));
scan = systable_beginscan(catalogRelation, DependDependerIndexId, true,
- SnapshotNow, 3, key);
+ NULL, 3, key);
while (HeapTupleIsValid(depTuple = systable_getnext(scan)))
{
@@ -9804,7 +9813,7 @@ ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId,
- true, SnapshotNow, 1, &key);
+ true, NULL, 1, &key);
if (HeapTupleIsValid(systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
@@ -10260,7 +10269,7 @@ AlterSeqNamespaces(Relation classRel, Relation rel,
/* we leave refobjsubid unspecified */
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
- SnapshotNow, 2, key);
+ NULL, 2, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-10 09:43:06 +0000