From: Alvaro Herrera Date: Fri, 12 Jul 2024 10:54:01 +0000 (+0200) Subject: Fix ALTER TABLE DETACH for inconsistent indexes X-Git-Tag: REL_12_20~27 X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=d0054432d480e958e4650c4b56de4a4a6e05da78;p=postgresql.git Fix ALTER TABLE DETACH for inconsistent indexes When a partitioned table has an index that doesn't support a constraint, but a partition has an equivalent index that does, then a DETACH operation would misbehave: a crash in assertion-enabled systems (because we fail to find the constraint in the parent that we expect to), or a broken coninhcount value (-1) in production systems (because we blindly believe that we've successfully detached the parent). While we should reject an ATTACH of a partition with such an index, we have failed to do so in existing releases, so adding an error in stable releases might break the (unlikely) existing applications that rely on this behavior. At this point I don't even want to reject them in master, because it'd break pg_upgrade if such databases exist, and there would be no easy way to fix existing databases without expensive index rebuilds. (Later on we could add ALTER TABLE ... ADD CONSTRAINT USING INDEX to partitioned tables, which would allow the user to fix such patterns. At that point we could add more restrictions to prevent the problem from its root.) Also, add a test case that leaves one table in this condition, so that we can verify that pg_upgrade continues to work if we later decide to change the policy on the master branch. Backpatch to all supported branches. Co-authored-by: Tender Wang Reported-by: Alexander Lakhin Reviewed-by: Tender Wang Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/18500-62948b6fe5522f56@postgresql.org --- diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index c0c707ca03b..5c2e64d4868 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -17066,22 +17066,31 @@ ATExecDetachPartition(Relation rel, RangeVar *name) foreach(cell, indexes) { Oid idxid = lfirst_oid(cell); + Oid parentidx; Relation idx; Oid constrOid; + Oid parentConstrOid; if (!has_superclass(idxid)) continue; - Assert((IndexGetRelation(get_partition_parent(idxid), false) == - RelationGetRelid(rel))); + parentidx = get_partition_parent(idxid); + Assert(IndexGetRelation(parentidx, false) == RelationGetRelid(rel)); idx = index_open(idxid, AccessExclusiveLock); IndexSetParentIndex(idx, InvalidOid); - /* If there's a constraint associated with the index, detach it too */ + /* + * If there's a constraint associated with the index, detach it too. + * Careful: it is possible for a constraint index in a partition to be + * the child of a non-constraint index, so verify whether the parent + * index does actually have a constraint. + */ constrOid = get_relation_idx_constraint_oid(RelationGetRelid(partRel), idxid); - if (OidIsValid(constrOid)) + parentConstrOid = get_relation_idx_constraint_oid(RelationGetRelid(rel), + parentidx); + if (OidIsValid(parentConstrOid) && OidIsValid(constrOid)) ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid); index_close(idx, NoLock); diff --git a/src/test/regress/expected/sanity_check.out b/src/test/regress/expected/sanity_check.out index deff49b07b5..c1ebf5a3749 100644 --- a/src/test/regress/expected/sanity_check.out +++ b/src/test/regress/expected/sanity_check.out @@ -171,6 +171,8 @@ quad_poly_tbl|t radix_text_tbl|t ramp|f real_city|f +regress_constr_partition1|t +regress_constr_partitioned|t road|t shighway|t slow_emp4000|f diff --git a/src/test/regress/input/constraints.source b/src/test/regress/input/constraints.source index d7996a5d837..47f2bfa0b4f 100644 --- a/src/test/regress/input/constraints.source +++ b/src/test/regress/input/constraints.source @@ -429,6 +429,46 @@ ALTER TABLE parted_fk_naming ATTACH PARTITION parted_fk_naming_1 FOR VALUES IN ( SELECT conname FROM pg_constraint WHERE conrelid = 'parted_fk_naming_1'::regclass AND contype = 'f'; DROP TABLE parted_fk_naming; +-- +-- Test various ways to create primary keys on partitions, linked to unique +-- indexes (without constraints) on the partitioned table. Ideally these should +-- fail, but we don't dare change released behavior, so instead cope with it at +-- DETACH time. +CREATE TEMP TABLE t (a integer, b integer) PARTITION BY HASH (a, b); +CREATE TEMP TABLE tp (a integer, b integer, PRIMARY KEY (a, b), UNIQUE (b, a)); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES WITH (MODULUS 1, REMAINDER 0); +CREATE UNIQUE INDEX t_a_idx ON t (a, b); +CREATE UNIQUE INDEX t_b_idx ON t (b, a); +ALTER INDEX t_a_idx ATTACH PARTITION tp_pkey; +ALTER INDEX t_b_idx ATTACH PARTITION tp_b_a_key; +ALTER TABLE t DETACH PARTITION tp; +SELECT conname, conparentid, conislocal, coninhcount + FROM pg_constraint WHERE conname IN ('tp_pkey', 'tp_b_a_key'); +DROP TABLE t, tp; + +CREATE TEMP TABLE t (a integer) PARTITION BY LIST (a); +CREATE TEMP TABLE tp (a integer PRIMARY KEY); +CREATE UNIQUE INDEX t_a_idx ON t (a); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES IN (1); +ALTER TABLE t DETACH PARTITION tp; +DROP TABLE t, tp; + +CREATE TEMP TABLE t (a integer) PARTITION BY LIST (a); +CREATE TEMP TABLE tp (a integer PRIMARY KEY); +CREATE UNIQUE INDEX t_a_idx ON ONLY t (a); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES IN (1); +ALTER TABLE t DETACH PARTITION tp; +DROP TABLE t, tp; + +CREATE TABLE regress_constr_partitioned (a integer) PARTITION BY LIST (a); +CREATE TABLE regress_constr_partition1 PARTITION OF regress_constr_partitioned FOR VALUES IN (1); +ALTER TABLE regress_constr_partition1 ADD PRIMARY KEY (a); +CREATE UNIQUE INDEX ON regress_constr_partitioned (a); +BEGIN; +ALTER TABLE regress_constr_partitioned DETACH PARTITION regress_constr_partition1; +ROLLBACK; +-- Leave this one in funny state for pg_upgrade testing + -- test a HOT update that invalidates the conflicting tuple. -- the trigger should still fire and catch the violation diff --git a/src/test/regress/output/constraints.source b/src/test/regress/output/constraints.source index 4a422442e58..2b4a06f8160 100644 --- a/src/test/regress/output/constraints.source +++ b/src/test/regress/output/constraints.source @@ -598,6 +598,48 @@ SELECT conname FROM pg_constraint WHERE conrelid = 'parted_fk_naming_1'::regclas (1 row) DROP TABLE parted_fk_naming; +-- +-- Test various ways to create primary keys on partitions, linked to unique +-- indexes (without constraints) on the partitioned table. Ideally these should +-- fail, but we don't dare change released behavior, so instead cope with it at +-- DETACH time. +CREATE TEMP TABLE t (a integer, b integer) PARTITION BY HASH (a, b); +CREATE TEMP TABLE tp (a integer, b integer, PRIMARY KEY (a, b), UNIQUE (b, a)); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES WITH (MODULUS 1, REMAINDER 0); +CREATE UNIQUE INDEX t_a_idx ON t (a, b); +CREATE UNIQUE INDEX t_b_idx ON t (b, a); +ALTER INDEX t_a_idx ATTACH PARTITION tp_pkey; +ALTER INDEX t_b_idx ATTACH PARTITION tp_b_a_key; +ALTER TABLE t DETACH PARTITION tp; +SELECT conname, conparentid, conislocal, coninhcount + FROM pg_constraint WHERE conname IN ('tp_pkey', 'tp_b_a_key'); + conname | conparentid | conislocal | coninhcount +------------+-------------+------------+------------- + tp_pkey | 0 | t | 0 + tp_b_a_key | 0 | t | 0 +(2 rows) + +DROP TABLE t, tp; +CREATE TEMP TABLE t (a integer) PARTITION BY LIST (a); +CREATE TEMP TABLE tp (a integer PRIMARY KEY); +CREATE UNIQUE INDEX t_a_idx ON t (a); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES IN (1); +ALTER TABLE t DETACH PARTITION tp; +DROP TABLE t, tp; +CREATE TEMP TABLE t (a integer) PARTITION BY LIST (a); +CREATE TEMP TABLE tp (a integer PRIMARY KEY); +CREATE UNIQUE INDEX t_a_idx ON ONLY t (a); +ALTER TABLE t ATTACH PARTITION tp FOR VALUES IN (1); +ALTER TABLE t DETACH PARTITION tp; +DROP TABLE t, tp; +CREATE TABLE regress_constr_partitioned (a integer) PARTITION BY LIST (a); +CREATE TABLE regress_constr_partition1 PARTITION OF regress_constr_partitioned FOR VALUES IN (1); +ALTER TABLE regress_constr_partition1 ADD PRIMARY KEY (a); +CREATE UNIQUE INDEX ON regress_constr_partitioned (a); +BEGIN; +ALTER TABLE regress_constr_partitioned DETACH PARTITION regress_constr_partition1; +ROLLBACK; +-- Leave this one in funny state for pg_upgrade testing -- test a HOT update that invalidates the conflicting tuple. -- the trigger should still fire and catch the violation BEGIN;