Re: BUG #19493: Assertion failure in pg_plan_advice with EXISTS subquery and DO_NOT_SCAN advice

Tender Wang <tndrwang@gmail.com>

From: Tender Wang <tndrwang@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Калинин Никита <n.kalinin@postgrespro.ru>, Michael Paquier <michael@paquier.xyz>, pgsql-bugs@lists.postgresql.org, Pierre Forstmann <pierre.forstmann@gmail.com>
Date: 2026-05-27T01:28:42Z
Lists: pgsql-bugs
Hi, all

Tender Wang <tndrwang@gmail.com> 于2026年5月27日周三 09:17写道:
>
> Tom Lane <tgl@sss.pgh.pa.us> 于2026年5月27日周三 09:08写道:
> >
> > =?UTF-8?B?0JrQsNC70LjQvdC40L0g0J3QuNC60LjRgtCw?= <n.kalinin@postgrespro.ru> writes:
> > > Could this be related to GCC? I'm using GCC 16.1.1 and I can reproduce the crash with that version.
> >
> > Maybe.  Does it still fail if you set the optimization level to -O0 ?
> I can reproduce this crash on my machine with CFLAGS="-O0 -g3". And my
> GCC version is 11.4.0
diff --git a/contrib/pg_plan_advice/pgpa_trove.c
b/contrib/pg_plan_advice/pgpa_trove.c
index ca69f3bd3df..0d15af1cbba 100644
--- a/contrib/pg_plan_advice/pgpa_trove.c
+++ b/contrib/pg_plan_advice/pgpa_trove.c
@@ -179,9 +179,18 @@ pgpa_build_trove(List *advice_items)
                                         * but in the future this
might not be true, e.g. a custom
                                         * scan could replace a join.
                                         */
-                                       Assert(target->ttype ==
PGPA_TARGET_IDENTIFIER);
-                                       pgpa_trove_add_to_slice(&trove->scan,
-
                 item->tag, target);
+                                       if (target->ttype ==
PGPA_TARGET_IDENTIFIER)
+
pgpa_trove_add_to_slice(&trove->scan,
+
                         item->tag, target);
+                                       else
+                                       {
+                                               Assert(target->ttype
== PGPA_TARGET_ORDERED_LIST);
+
foreach_ptr(pgpa_advice_target, child_target, target->children)
+                                               {
+
pgpa_trove_add_to_slice(&trove->scan,
+
                         item->tag, child_target);
+                                               }
+                                       }
                                }

I tried the above fix, and no crash again.



-- 
Thanks,
Tender Wang



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. pg_plan_advice: DO_NOT_SCAN is a simple tag, not a generic one.

  2. doc: add comma to UPDATE docs, for consistency

  3. Add stack depth check to QueueFKConstraintValidation().