Re: [SQL] Vacuum takes more than 1 hr

Instead of using CVS, will ftp'ing the postgresql.snapshot.tar.gz file do? I
looked around for an explanation of what this file is, but didn't find any.

----- Original Message -----
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Postgres <postgres@weblynk.com>
Cc: pgsql-sql@postgresql.org <pgsql-sql@postgreSQL.org>
Sent: Monday, October 25, 1999 7:45 AM
Subject: Re: [SQL] Vacuum takes more than 1 hr


> Postgres <postgres@weblynk.com> writes:
> > I have a table with about 30 columns and 200K rows. When I perform a
vacuum
> > on it (no analyze) it takes usually a little more than 1 hour.
>
> Hmm, doesn't seem all that large.  One question is whether you are all
> the way up-to-date on Postgres --- some performance problems in vacuum
> were fixed recently.  (The problems were excessive memory usage,
> actually, but that could translate to long runtime if the process
> started to swap.  Does the backend that's doing the vacuum seem to grow
> to a size much larger than it starts at?)  I don't recall whether this
> patch is in 6.5.2 or not, but it will be in 6.5.3, or you could pull
> the current REL6_5 branch sources from the CVS server.
>
> A performance problem that still remains is that vacuum seems
> unreasonably slow at updating indexes.  Some people have found that
> dropping and recreating indexes around a vacuum nets out faster than
> letting vacuum do it.  You should also ask yourself whether each
> index on the table is earning its keep --- each one costs time on
> every insert or update, quite aside from vacuum.  Only the indexes
> that actually get used for your common queries are likely to be worth
> their overhead.
>
> regards, tom lane
>
> ************