Re: performance question on VACUUM FULL (Postgres 8.4.2)

On Tue, 2010-01-19 at 12:19 -0800, PG User 2010 wrote:
> Hello,
>
> We are running into some performance issues with running VACUUM FULL
> on the pg_largeobject table in Postgres (8.4.2 under Linux), and I'm
> wondering if anybody here might be able to suggest anything to help
> address the issue.

Are you running VACUUM (without FULL) regularly? And if so, is that
insufficient?

> Our pg_largeobject table is about 200 gigabytes, and I suspect that
> about 30-40% of the table are dead rows (after having run vacuumlo and
> deleting large numbers of large objects).

You can always expect some degree of bloat. Can you give an exact number
before and after the VACUUM FULL? Or is this a one-shot attempt that
never finished?

If large objects are being added/removed regularly, it might be better
just to wait (and do regular VACUUMs), and the table will naturally
compact after the rows at the end are removed.

Regards,
    Jeff Davis