Re: strange behavior (corruption?) of large production database

Joe Conway <mail@joeconway.com> writes:
> So they agree in template1 and cyspec databases.

OK, in that case I'd wonder about whether you've suffered XID wraparound
in pg_database and/or pg_shadow.  The typical symptom of this is that
entries are valid from the system's point of view but not visible to
queries, and that seems to be what you have.  If so, a restart will NOT
fix it.  You could try a VACUUM FREEZE on pg_database though.  Before
doing that, I'd suggest looking at the rows' xmin values (use
pg_filedump or grovel through the bits by hand) to confirm the
wraparound theory.
        regards, tom lane