Re: Could not finish anti-wraparound VACUUM when stop limit is reached

On Sun, May 25, 2014 at 8:53 AM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:

> On 2014-05-25 11:40:09 -0400, Heikki Linnakangas wrote:
> > So, vac_truncate_clog() tries to get a new transaction ID, which fails
> > because we've already reached the stop-limit. vac_truncate_clog() doesn't
> > really need a new XID to be assigned, though, it only uses it to compare
> > against datfrozenxid to see if wrap-around has already happened, so it
> could
> > use ReadNewTransactionId() instead.
>
> Right. But IIRC we need one in the vicinity anyway to write new
> pg_database et al rows?
>

pg_database and pg_class are updated with heap_inplace_update in these
cases.

The page gets a new LSN, but the tuples do not get a new transaction ID.

Cheers,

Jeff