Of course I cannot say if this is your case, but I've been using PG since 2004 and every single instance* of a segfault has turned out to be caused by some 3rd-party extension or other. And yes, the extension was never related in any way to the query being run, it just corrupted memory such that PG would die later. So I would audit extensions, and see if any have been recently added, any could be removed temporarily, and so on. * It's only 2 or 3 cases in all that time, but still, it was never core PG. -- Scott Ribe scott_ribe@xxxxxxxxxxxxxxxx https://www.linkedin.com/in/scottribe/ > On Oct 29, 2021, at 8:05 AM, Tyler Brock <tyler.brock@xxxxxxxxx> wrote: > > Hi all, > > I keep getting segfaults when running queries against postgresql replicas. We have an ETL job that hits these nodes with many small queries (no more than 8 concurrently) and the box has 16 cores and plenty of I/O and ram. > > However, during this process postgresql segfaults, usually on COPY commands that have this shape: > > COPY > ( > SELECT row_to_json(t) > FROM ( > SELECT lead_tag."objectId" AS "lead_id", > lead_tag."tag" AS "tag_id" > FROM ( > SELECT "objectId", > jsonb_array_elements_text("tags") AS tag > FROM "Lead" > WHERE true > AND "Lead"."organization" = 'I6JDWAaZx5' > AND tags IS NOT NULL > AND "Lead"."updatedAt" >= '2015-01-01' > AND "Lead"."updatedAt" < '2021-10-30T11:05:40.389773+00:00' ) AS lead_tag) t) TO stdout > > Is there anything I can do to prevent this or anything i can look at to try and diagnose what is happening here? I’m running Postgres 12.7 and cannot tell if this is a symptom of a bug or just misconfiguration. > > What I see in the error logs is: > > 2021-10-29 11:08:10 UTC:172.23.17.171(54332):postgres@postgres:[22200]:ERROR: cache lookup failed for type 0 > 2021-10-29 11:08:10 UTC:172.23.17.171(54332):postgres@postgres:[22200]:STATEMENT: COPY (SELECT ROW_TO_JSON(t) FROM (… the query above...) TO STDOUT > 2021-10-29 11:08:10 UTC::@:[19406]:LOG: server process (PID 22200) was terminated by signal 11: Segmentation fault > > > Any help would be greatly appreciated, thanks! > > -Tyler
