Re: Re: VACUUM is hanging

On Fri, May 04, 2001 at 09:44:10PM -0500, Ashley Clark wrote:
> * Tom Lane in "Re: VACUUM is hanging" dated 2001/05/04 22:05 wrote:
>
> > > I also seem to have found the culprit. I have Apache::DBI set up
> > > and it's holding something open. Restarting Apache let the vacuum
> > > finish normally.
> >
> > Try not to leave open transactions hanging around in your Apache
> > code. An idle database connection couldn't block VACUUM like that;
> > it'd have to have been in the middle of a BEGIN block, or maybe even
> > an unfinished query.
>
> That appears to be the culprit. I don't really understand why an
> uncommitted SELECT statement could/should lock the table though. How
> does that differ from just an open transaction where no query has
> happened yet?

If you are using Apache::DBI (as you mentioned previously), I
don't think this can be the case. Apache::DBI registers a
PerlCleanupHandler with Apache which will rollback any
uncommitted transactions after every request.

Cheers,

Neil