Hi, On Mon, Mar 23, 2026 at 3:57 PM Chao Li <[email protected]> wrote: > > > > > On Mar 21, 2026, at 18:29, Xuneng Zhou <[email protected]> wrote: > > > > On Thu, Mar 19, 2026 at 1:07 PM Chao Li <[email protected]> wrote: > >> > >> > >> > >>> On Feb 26, 2026, at 14:59, Chao Li <[email protected]> wrote: > >>> > >>> > >>> > >>>> On Jan 28, 2026, at 10:49, Chao Li <[email protected]> wrote: > >>>> > >>>> > >>>> > >>>>> On Jan 27, 2026, at 16:30, Chao Li <[email protected]> wrote: > >>>>> > >>>>> > >>>>> > >>>>>> On Jan 27, 2026, at 15:59, Chao Li <[email protected]> wrote: > >>>>>> > >>>>>> > >>>>>> > >>>>>>> On Jan 27, 2026, at 15:39, Michael Paquier <[email protected]> wrote: > >>>>>>> > >>>>>>> On Tue, Jan 27, 2026 at 01:13:32PM +0800, Chao Li wrote: > >>>>>>>> I found this bug while working on a related patch [1]. > >>>>>>>> > >>>>>>>> When ALTER TABLE ... ALTER COLUMN TYPE causes an index rebuild, and > >>>>>>>> that index is used as REPLICA IDENTITY on a partitioned table, the > >>>>>>>> replica identity marking on partitions can be silently lost after the > >>>>>>>> rebuild. > >>>>>>> > >>>>>>> I am slightly confused by the tests included in the proposed patch. > >>>>>>> On HEAD, if I undo the proposed changes of tablecmds.c, the tests > >>>>>>> pass. If I run the tests of the patch with the changes of > >>>>>>> tablecmds.c, the tests also pass. > >>>>>> > >>>>>> Oops, that isn’t supposed to be so. I’ll check the test. > >>>>>> > >>>>> > >>>>> Okay, I see the problem is here: > >>>>> ``` > >>>>> +CREATE UNIQUE INDEX test_replica_identity_partitioned_pkey ON test_replica_identity_partitioned (id); > >>>>> ``` > >>>>> > >>>>> I missed to add column “val” into the index, so that alter type of val didn’t cause index rebuild. > >>>>> > >>>>> Ideally, it’s better to also verify that index OIDs should have changed before and after alter column type, but I haven’t figured out how to do so. Do you have an idea? > >>>> > >>>> I just updated the test to store index OIDs before and after rebuild into 2 temp tables, so that we can compare the OIDs to verify rebuild happens and replica identity preserved. > >>>> > >>>> I tried to port the test to master branch, and the test failed. From the test diff file, we can see replica identity lost on 3 leaf partitions: > >>>> ``` > >>>> @@ -360,9 +360,9 @@ > >>>> ORDER BY b.index_name; > >>>> index_name | rebuilt | ri_lost > >>>> ---------------------------------------------------+---------+--------- > >>>> - test_replica_identity_partitioned_p1_id_val_idx | t | f > >>>> - test_replica_identity_partitioned_p2_1_id_val_idx | t | f > >>>> - test_replica_identity_partitioned_p2_2_id_val_idx | t | f > >>>> + test_replica_identity_partitioned_p1_id_val_idx | t | t > >>>> + test_replica_identity_partitioned_p2_1_id_val_idx | t | t > >>>> + test_replica_identity_partitioned_p2_2_id_val_idx | t | t > >>>> test_replica_identity_partitioned_p2_id_val_idx | t | f > >>>> test_replica_identity_partitioned_pkey | t | f > >>>> (5 rows) > >>>> ``` > >>>> > >>>> With this patch, the test passes and all replica identity are preserved. > >>>> > >>>> PFA v3: > >>>> * Enhanced the test. > >>>> * A small change in find_partition_replica_identity_indexes(): if we will not update a partition, then unlock it. > >>>> > >>>> Best regards, > >>>> -- > >>>> Chao Li (Evan) > >>>> HighGo Software Co., Ltd. > >>>> https://www.highgo.com/ > >>>> > >>>> > >>>> > >>>> > >>>> <v3-0001-tablecmds-fix-bug-where-index-rebuild-loses-repli.patch> > >>> > >>> The CF asked for a rebase, thus rebased as v4. > >>> > > > > > > Hi, I reproduced this with the test case, and the patch appears > > to resolve it. > > > > Some comments on v5: > > Thanks a lot for your review. > > > > > -- Whether it makes sense to use a single list of pair structs instead > > of two parallel OID lists (replicaIdentityIndexOids + > > replicaIdentityTableOids) to avoid accidental desync. > > I don’t think that helps much. The current code of rebuilding index uses two lists changedIndexOids and changedIndexDefs. So, this patch matches the pattern of the existing code. > > > > > -- It would be better to make lock handling in > > find_partition_replica_identity_indexes() consistent > > (relation_open(..., NoLock) if child is already locked, and avoid > > mixed relation_close(..., lockmode)/NoLock behavior). > > That’s because if we are going to update a partition, then we need to hold the lock on the partition.
There is one locking cleanup in find_partition_replica_identity_indexes(). find_inheritance_children(relId, lockmode) already acquires lockmode on every partition it returns, so I think the later relation_open() should use NoLock, not lockmode. For the same reason, all relation_close() calls in this function should use NoLock as well. Today the code does: partRel = relation_open(partRelOid, lockmode); ... relation_close(partRel, lockmode); That does not cause a correctness issue, because the lock manager reference-counts same-transaction acquisitions, so the lock remains held either way. But it is misleading: it suggests that relation_open() is where the partition lock is taken, and that the early relation_close(..., lockmode) is intentionally releasing it. Neither is actually true here, because the lock was already acquired by find_inheritance_children(). So I think this should be adjusted to: partRel = relation_open(partRelOid, NoLock); and all close sites in this function should be: relation_close(partRel, NoLock); The comment on the early-close path should also be updated, since it is not really unlocking the partition. Something like "No matching partition index; just close the relcache entry" would match the actual behavior better. > > > > -- Some typos in comments/tests (partion/parition). > > > > Fixed. > > PFA v6: fixed a typo in comment. > > Best regards, > -- > Chao Li (Evan) > HighGo Software Co., Ltd. > https://www.highgo.com/ > > > > -- Best, Xuneng
