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 <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Discussion: https://postgr.es/m/18550-d5e047e9a897a889@postgresql.org

diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 8cf2584522234a1957c0e95d24b7a92b7672f7af..75b33c7af165e0af13f1c397c0703262b83f7ced 100644 (file)
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -3845,6 +3845,14 @@ 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 d90a5d0eb91ec35b0e6f009ab70007ab28a118ba..a55cd48114999d5af3added06843425c1a8cf9e7 100644 (file)
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3754,8 +3754,16 @@ 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 1c34da8658a9d4b44249fea1ff08b88d61c46f0a..a04d41b1e248062eb21bf6d1f104364e0fbe2dca 100644 (file)
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -2362,6 +2362,13 @@ 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