Re: "PANIC: could not open critical system index 2662" - twice

On Fri, May 5, 2023 at 11:15 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> What does select
> pg_relation_filepath('pg_class_oid_index') show in the corrupted
> database, base/5/2662 or something else?

Oh, you can't get that far, but perhaps you could share the
pg_filenode.map file?  Or alternatively strace -f PostgreSQL while
it's starting up to see which file it's reading, just to be sure.  One
way to find clues about whether PostgreSQL did something wrong, once
we definitely have the right relfilenode for the index, aside from
examining its contents, would be to search the WAL for references to
that block with pg_waldump.  Maybe you still have enough WAL if it
happened recently?