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

diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 987b53ba19d176936f4b8e94d16bf4e48f495868..3bfd4c6245020ede3378e2ffbb3d3ce49e8d737e 100644 (file)
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -3808,6 +3808,14 @@ 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);

diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 47d26ef632ceba8e4a3c7e94d71e2a00bca3692a..28afffad2f05b74b2c635b03b2f3cdbbe7008c3d 100644 (file)
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3911,8 +3911,16 @@ 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);

diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 53e62c5ff9be79c8d481a02ad0a22087d783f559..d1b9f067152b6ae0de834c4b7c68897ab792a635 100644 (file)
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -2413,6 +2413,13 @@ 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