Re: Lost tables in Postgres 7.1

Steve Burrows <steve@jla.com> writes:
> Some of my tables have spontaneously disappeared. They are not visible
> in pg_class. vacuuming pg_class (as suggested by Tom Lane for someone
> with a similar problem) did not cause them to reappear.

Not on 7.1 it wouldn't :-(.  That hack is dependent on the behavior of
the transaction ID wraparound code that we introduced in 7.2.

First check if this actually is a wrap issue: create a new row and see
if its xmin is small or large.  If small, I think the only recourse in
7.1 is to set the XID counter to something just a bit less than 4G,
pg_dump, initdb and reload.  If you dig around in the archives from
a few years back you should find discussion of exactly how to do that,
but I've surely forgotten the details.

            regards, tom lane