Re: missing data

Dave Perkins <drp@shore.net> writes:
> Thanks for your time and patience . . . The only entries I see in the
> pg_class table are relnames with the 'pg_' prefix.  They all have a
> relowner (40) that matches the only record listed in the pg_shadow
> table.  The fact that the database in question does not have a
> corresponding entry in the pg_database seems to be most revealing if only I
> understood what it is revealing . . .  The one other piece of evidence I
> have is the "Couldn't find any tables!" error message when executing the
> \dt command, yet when I run a select * for a relation that use to exist, it
> gives an acurate listing of field names, but no records (ie. missing data).

The "couldn't find any tables" complaint makes sense if pg_class isn't
showing any entries for user-defined tables.  I don't quite understand
how it's letting you do a select from a table that's not visible in
pg_class, however.

Is it possible that you've executed more than 4 billion transactions
against this database?  If so you might be suffering from ye infamous
XID wraparound problem.  Look at pg_log in the $PGDATA directory; if
it's a gigabyte or so in size then this might have happened.

            regards, tom lane