Re: [BUG] Fix DETACH with FK pointing to a partitioned table fails - Mailing list pgsql-hackers

On Fri, Jul 26, 2024 at 2:36 PM Junwang Zhao <zhjwpku@gmail.com> wrote:
>
> On Mon, Jul 22, 2024 at 1:52 PM Tender Wang <tndrwang@gmail.com> wrote:
> >
> >
> >
> > Alvaro Herrera <alvherre@alvh.no-ip.org> 于2024年7月19日周五 21:18写道：
> >>
> >> Hello,
> >>
> >> I think the fix for the check triggers should be as the attached.  Very
> >> close to what you did, but you were skipping some operations that needed
> >> to be kept.  AFAICS this patch works correctly for the posted cases.
> >
> >
> > After applying the attached, the r_1_p_id_fkey1 will have redundant action
> > triggers, as below:
> > postgres=# select oid, conname, contype, conrelid, conindid,conparentid, confrelid,conislocal,coninhcount,
connoinheritfrom pg_constraint where oid = 16402; 
> >   oid  |    conname     | contype | conrelid | conindid | conparentid | confrelid | conislocal | coninhcount |
connoinherit
> >
-------+----------------+---------+----------+----------+-------------+-----------+------------+-------------+--------------
> >  16402 | r_1_p_id_fkey1 | f       |    16394 |    16392 |           0 |     16389 | t          |           0 | f
> > (1 row)
> >
> > postgres=# select oid, tgrelid, tgparentid, tgconstrrelid, tgconstrindid, tgconstraint from pg_trigger where
tgconstraint= 16402; 
> >   oid  | tgrelid | tgparentid | tgconstrrelid | tgconstrindid | tgconstraint
> > -------+---------+------------+---------------+---------------+--------------
> >  16403 |   16389 |      16400 |         16394 |         16392 |        16402
> >  16404 |   16389 |      16401 |         16394 |         16392 |        16402
> >  16422 |   16389 |          0 |         16394 |         16392 |        16402
> >  16423 |   16389 |          0 |         16394 |         16392 |        16402
> > (4 rows)
> >
>
> Yes, seems Alvaro has mentioned that he hasn't looked at the
> action triggers, in the attached patch, I add some logic that
> first check if there exists action triggers, if yes, just update
> their Parent Trigger to InvalidOid.
>
> >
> > --
> > Tender Wang
>
>
>
> --
> Regards
> Junwang Zhao

There is a bug report[0] Tender comments might be the same
issue as this one, but I tried Alvaro's and mine patch, neither
could solve that problem, I did not tried Tender's earlier patch
thought. I post the test script below in case you are interested.

CREATE TABLE t1 (a int, PRIMARY KEY (a));
CREATE TABLE t (a int, PRIMARY KEY (a), FOREIGN KEY (a) REFERENCES t1)
PARTITION BY LIST (a);
ALTER TABLE t ATTACH PARTITION t1 FOR VALUES IN (1);
ALTER TABLE t DETACH PARTITION t1;
ALTER TABLE t ATTACH PARTITION t1 FOR VALUES IN (1);


[0] https://www.postgresql.org/message-id/18541-628a61bc267cd2d3@postgresql.org

--
Regards
Junwang Zhao