Re: PostgreSQL 12 - ERROR: invalid attribute number 2 for ad_user_pkey - Urgent

FOUTE K. Jaurès <jauresfoute@gmail.com> writes:
> For all table except the pg_catalo table.
> The dump on the database is not possible too. (pg_dump: error: invalid
> column numbering in table "xxxxxx")

It seems that pg_attribute is messed up.  If you are really lucky,
it might be only a problem in pg_attribute's indexes, in which case
reindexing pg_attribute would fix it.  However, I recommend proceeding
on the assumption that you have possibly-irrecoverable damage.  Before
you do ANYTHING, make a complete filesystem-level backup of the cluster
(stop the server, then do "tar cf backup.tar $PGDATA" or equivalent).

Even if reindexing pg_attribute seems to fix it, I'd counsel then doing
a pg_dump and restore, in hopes of curing any other problems that may
have stemmed from the same root cause.

Speaking of root cause, have you had any crashes lately?  Is your
Postgres up-to-date?  How about the underlying OS?

                        regards, tom lane