Re: PATCH to allow concurrent VACUUMs to not lock each

On E, 2005-05-23 at 11:42 -0400, Tom Lane wrote:
> Hannu Krosing <hannu(at)skype(dot)net> writes:
> > I can't think of any other cases where it could matter, as at least the
> > work done inside vacuum_rel() itself seema non-rollbackable.
>
> VACUUM FULL's tuple-moving is definitely roll-back-able, so it might be
> prudent to only do this for lazy VACUUM. But on the other hand, VACUUM
> FULL holds an exclusive lock on the table so no one else is going to see
> its effects concurrently anyway.

Ok, this is a new version of the vacuum patch with the following changes
following some suggestions in this thread.

* changed the patch to affect only lazy vacuum
* moved inVacuum handling to use PG_TRY
* moved vac_update_relstats() out of lazy_vacuum_rel into a separate
transaction. The code to do this may not be the prettiest, maybe it
should use a separate struct.

--
Hannu Krosing <hannu(at)skype(dot)net>