Re: BUG #17817: DISABLE TRIGGER ALL on a partitioned table with foreign key fails

PG Bug reporting form <noreply@postgresql.org> writes:
> This works on 14.7. It fails on 15.2. The Ruby on Rails test suites use
> DISABLE TRIGGER ALL extensively.

> BEGIN;
> CREATE TABLE test_fk (id serial primary key);
> CREATE TABLE test_table (test serial, created_at timestamp not null, fk_id
> int not null references test_fk(id)) PARTITION BY RANGE (created_at);
> CREATE TABLE test_table_2017 PARTITION OF test_table FOR VALUES FROM
> ('2017-01-01') TO ('2018-01-01');
> ALTER TABLE test_table DISABLE TRIGGER ALL;
> ROLLBACK;
> ERROR:  trigger "RI_ConstraintTrigger_c_46838897" for table
> "test_table_2017" does not exist

Yeah, duplicated here.  Bisecting says it broke at

commit ec0925c22a3da7199650c9903a03a0017705ed5c
Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date:   Thu Aug 4 20:02:02 2022 +0200

    Fix ENABLE/DISABLE TRIGGER to handle recursion correctly

    Using ATSimpleRecursion() in ATPrepCmd() to do so as bbb927b4db9b did is
    not correct, because ATPrepCmd() can't distinguish between triggers that
    may be cloned and those that may not, so would wrongly try to recurse
    for the latter category of triggers.

    So this commit restores the code in EnableDisableTrigger() that
    86f575948c77 had added to do the recursion, which would do it only for
    triggers that may be cloned, that is, row-level triggers.  This also
    changes tablecmds.c such that ATExecCmd() is able to pass the value of
    ONLY flag down to EnableDisableTrigger() using its new 'recurse'
    parameter.

Interestingly, although that commit was back-patched to v11, the failure
does not occur in pre-v15 branches.  So what's different about v15?

One clue is that the contents of pg_trigger are quite a bit different:

# select oid, tgparentid, tgrelid::regclass, tgname from pg_trigger where tgrelid in ('test_fk'::regclass,
'test_table'::regclass,'test_table_2017'::regclass); 
  oid  | tgparentid |     tgrelid     |            tgname
-------+------------+-----------------+------------------------------
 40997 |          0 | test_fk         | RI_ConstraintTrigger_a_40997
 40998 |          0 | test_fk         | RI_ConstraintTrigger_a_40998
 40999 |          0 | test_table      | RI_ConstraintTrigger_c_40999
 41000 |          0 | test_table      | RI_ConstraintTrigger_c_41000
 41006 |      40999 | test_table_2017 | RI_ConstraintTrigger_c_41006
 41007 |      41000 | test_table_2017 | RI_ConstraintTrigger_c_41007
(6 rows)

# ALTER TABLE test_table DISABLE TRIGGER ALL;
ERROR:  trigger "RI_ConstraintTrigger_c_40999" for table "test_table_2017" does not exist

whereas in v14 I see

# select oid, tgparentid, tgrelid::regclass, tgname from pg_trigger where tgrelid in ('test_fk'::regclass,
'test_table'::regclass,'test_table_2017'::regclass); 
  oid  | tgparentid |     tgrelid     |            tgname
-------+------------+-----------------+------------------------------
 38169 |          0 | test_fk         | RI_ConstraintTrigger_a_38169
 38170 |          0 | test_fk         | RI_ConstraintTrigger_a_38170
 38176 |          0 | test_table_2017 | RI_ConstraintTrigger_c_38176
 38177 |          0 | test_table_2017 | RI_ConstraintTrigger_c_38177
(4 rows)

It's a reasonable bet that we're trying to look up the child trigger
using the name of its parent trigger ... but why are we searching by
name at all, rather than OID?  Seems mighty failure-prone.

Stack trace from the lookup failure is

#0  errfinish (filename=0xac4aeb "trigger.c", lineno=1838,
    funcname=0xad8fe0 <__func__.30665> "EnableDisableTrigger") at elog.c:480
#1  0x00000000004c968f in EnableDisableTrigger (rel=<optimized out>,
    tgname=0x7f10283ad88c "RI_ConstraintTrigger_c_40999",
    fires_when=<optimized out>, skip_system=false, recurse=true, lockmode=6)
    at trigger.c:1835
#2  0x000000000069a717 in EnableDisableTrigger (rel=rel@entry=0x7f1031892768,
    tgname=tgname@entry=0x0, fires_when=fires_when@entry=68 'D',
    skip_system=false, recurse=true, lockmode=6) at trigger.c:1819
#3  0x0000000000691db4 in ATExecEnableDisableTrigger (
    lockmode=<optimized out>, recurse=<optimized out>,
    skip_system=<optimized out>, fires_when=<optimized out>,
    trigname=<optimized out>, rel=<optimized out>) at tablecmds.c:14729
#4  ATExecCmd (wqueue=0x7fffb8534408, tab=0x17f4788, cmd=<optimized out>,
    lockmode=6, cur_pass=<optimized out>, context=0x7fffb85345a0)
    at tablecmds.c:5165
#5  0x0000000000693108 in ATRewriteCatalogs (context=0x7fffb85345a0,
    lockmode=6, wqueue=0x7fffb8534408)
    at ../../../src/include/nodes/nodes.h:193

            regards, tom lane