Re: Interesting fail when migrating Pg from Ubuntu Bionic to Focal

On Thu, Mar 03, 2022 at 05:39:21PM +0100, hubert depesz lubaczewski wrote:
> On Thu, Mar 03, 2022 at 04:11:56PM +0100, hubert depesz lubaczewski wrote:
> > On Thu, Mar 03, 2022 at 04:04:28PM +0100, hubert depesz lubaczewski wrote:
> > > and it worked, so I'm kinda at loss here.
> >
> > based on some talk on IRC, I was able to get stack trace from fail:
>
> Based on the stack trace I was able to get it to break using simple
> query:
> select p.proname, (SELECT rolname from pg_catalog.pg_roles where oid = p.proowner) from pg_proc p;
>
> I took a simple look at ranges of oid/prowner, and they look fine:
>
> =# select min(proowner), max(proowner), count(*) from pg_proc;
> min │ max │ count
> ─────┼─────┼───────
> 10 │ 10 │ 2970
> (1 row)
>
> 16:38:34 db: postgres(at)postgres, pid:1991057
> =# select min(oid), max(oid), count(*) from pg_roles;
> min │ max │ count
> ─────┼───────────┼───────
> 10 │ 310235824 │ 244
> (1 row)
>
>
> Also, as I didn't mention it before: it's Pg 12.9.

OK. Traced it back to JIT. With JIT enabled:

=# show jit;
jit
─────
on
(1 row)

=# explain select p.proname, (SELECT rolname from pg_catalog.pg_roles where oid = p.proowner) from pg_proc p;
QUERY PLAN
──────────────────────────────────────────────────────────────────────────────────────────────
Seq Scan on pg_proc p (cost=0.00..156507.84 rows=63264 width=128)
SubPlan 1
-> Index Scan using pg_authid_oid_index on pg_authid (cost=0.14..2.36 rows=1 width=64)
Index Cond: (oid = p.proowner)
JIT:
Functions: 8
Options: Inlining false, Optimization false, Expressions true, Deforming true
(7 rows)

=# select p.proname, (SELECT rolname from pg_catalog.pg_roles where oid = p.proowner) from pg_proc p;
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
16:42:44 canvas test, cluster 999, standalone db: @, pid:2014255
?!>

But when I disable jit - query works fine.

versions of things that I think are relevant:

=$ dpkg -l | grep -E 'llvm|clang|gcc|glibc'
ii gcc 4:9.3.0-1ubuntu2 arm64 GNU C compiler
ii gcc-10-base:arm64 10.3.0-1ubuntu1~20.04 arm64 GCC, the GNU Compiler Collection (base package)
ii gcc-9 9.3.0-17ubuntu1~20.04 arm64 GNU C compiler
ii gcc-9-base:arm64 9.3.0-17ubuntu1~20.04 arm64 GCC, the GNU Compiler Collection (base package)
ii libgcc-9-dev:arm64 9.3.0-17ubuntu1~20.04 arm64 GCC support library (development files)
ii libgcc-s1:arm64 10.3.0-1ubuntu1~20.04 arm64 GCC support library
ii libllvm9:arm64 1:9.0.1-12 arm64 Modular compiler and toolchain technologies, runtime library

Best regards,

depesz