Reset relhassubclass upon attaching table as a partition

We don't allow inheritance parents as partitions, and have checks to
prevent this; but if a table _was_ in the past an inheritance parents
and all their children are removed, the pg_class.relhassubclass flag
may remain set, which confuses the partition pruning code (most
obviously, it results in an assertion failure; in production builds it
may be worse.)

Fix by resetting relhassubclass on attach.

Backpatch to all supported versions.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18550-d5e047e9a897a889@postgresql.org
This commit is contained in:
Alvaro Herrera 2024-07-24 12:38:18 +02:00
parent 547dd2cbda
commit f74fac06c6
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
3 changed files with 24 additions and 1 deletions

View File

@ -3518,6 +3518,14 @@ StorePartitionBound(Relation rel, Relation parent, PartitionBoundSpec *bound)
new_val, new_null, new_repl);
/* Also set the flag */
((Form_pg_class) GETSTRUCT(newtuple))->relispartition = true;
/*
* We already checked for no inheritance children, but reset
* relhassubclass in case it was left over.
*/
if (rel->rd_rel->relkind == RELKIND_RELATION && rel->rd_rel->relhassubclass)
((Form_pg_class) GETSTRUCT(newtuple))->relhassubclass = false;
CatalogTupleUpdate(classRel, &newtuple->t_self, newtuple);
heap_freetuple(newtuple);
table_close(classRel, RowExclusiveLock);

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@ -3909,8 +3909,16 @@ ALTER TABLE list_parted ATTACH PARTITION child FOR VALUES IN (1);
ERROR: cannot attach inheritance child as partition
ALTER TABLE list_parted ATTACH PARTITION parent FOR VALUES IN (1);
ERROR: cannot attach inheritance parent as partition
DROP TABLE child;
-- now it should work, with a little tweak
ALTER TABLE parent ADD CONSTRAINT check_a CHECK (a > 0);
ALTER TABLE list_parted ATTACH PARTITION parent FOR VALUES IN (1);
-- test insert/update, per bug #18550
INSERT INTO parent VALUES (1);
UPDATE parent SET a = 2 WHERE a = 1;
ERROR: new row for relation "parent" violates partition constraint
DETAIL: Failing row contains (2, null).
DROP TABLE parent CASCADE;
NOTICE: drop cascades to table child
-- check any TEMP-ness
CREATE TEMP TABLE temp_parted (a int) PARTITION BY LIST (a);
CREATE TABLE perm_part (a int);

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@ -2410,6 +2410,13 @@ CREATE TABLE parent (LIKE list_parted);
CREATE TABLE child () INHERITS (parent);
ALTER TABLE list_parted ATTACH PARTITION child FOR VALUES IN (1);
ALTER TABLE list_parted ATTACH PARTITION parent FOR VALUES IN (1);
DROP TABLE child;
-- now it should work, with a little tweak
ALTER TABLE parent ADD CONSTRAINT check_a CHECK (a > 0);
ALTER TABLE list_parted ATTACH PARTITION parent FOR VALUES IN (1);
-- test insert/update, per bug #18550
INSERT INTO parent VALUES (1);
UPDATE parent SET a = 2 WHERE a = 1;
DROP TABLE parent CASCADE;
-- check any TEMP-ness