Re: pg_dump: ERROR: could not open relation with OID ...

Thomas F. O'Connell wrote:
> During a routine backup procedure (that does not run nightly) for an
> 8.2.3 postgres cluster, pg_dump failed:
>
> pg_dump: Error message from server: ERROR:  could not open relation
> with OID ...
>
> In doing some log forensics, I discovered that this error has been
> showing up in the logs intermittently unconnected to pg_dump for the
> past 6 days. It's not occurring at an alarming rate, but the fact
> that it's occurring at all is mildly alarming, and the fact that it's
> preventing backups is even more alarming.
>
> In reviewing the logs, one OID in particular shows up in the vast
> majority of the errors, and it doesn't correspond to any entries I
> can find in pg_class. A handful of other OIDs show up, and a sampling
> of them reveals, too, no entries in pg_class.

OIDs that show up more than a couple of times are likely to be stored in
a catalog somewhere.  The first place I'd look is pg_depend and
pg_shdepend.  Other places that mention OIDs related to relations are
pg_constraint, pg_rewrite, pg_description, pg_shdescription, pg_trigger,
pg_type, pg_autovacuum; but all of them would most likely be used only
if a pg_class tuple references those, so it's unlikely that it's those
at fault.

--
Alvaro Herrera                               http://www.PlanetPostgreSQL.org/
"No necesitamos banderas
 No reconocemos fronteras"                  (Jorge González)