Re: Is Vacuum Working ?

"Thorne, Francis" <thornef@cromwell.co.uk> writes:
> Information in Log file after database restart

> 01/08/2009 - Next Transaction ID = 1400435363
> 01/09/2009 - Next Transaction ID = 1462025864

> Transaction_ID Wrapwround limit is 214784146 limited by database
> postgres

> Is this normal, I would have thought the transactional ID would have
> stayed roughly the same due to vacuum ? If this keeps increasing will it
> mean I am getting to close my 2 billion transaction limit ?

Yeah, this looks perfectly normal.  VACUUM doesn't make the next-XID
counter go backwards.  What it will do from time to time is push out the
wraparound limit (by "freezing" very old rows' XID numbers).  As long as
there's a few million transactions' worth of daylight between the wrap
limit and current XIDs, there's nothing to worry about.

            regards, tom lane