"Michael Beckstette" <mbeckste@TechFak.Uni-Bielefeld.DE> writes:
> we recently discovered on our production database an a little bit bizarre
> problem (after two years stable operations). Some tables are simply missing, or
> sometimes the affected table(s) is/are there but not listed in pg_tables.
This sounds a bit like a transaction ID wraparound problem. Have you
been vacuuming your whole database on a reasonable schedule? The
missing tables might conceivably be old enough that their pg_class rows
have wrapped around "into the future". It'd be useful to look at
SELECT datname, age(datfrozenxid) FROM pg_database;
regards, tom lane