Re: Postgresqlism & Vacuum?

Bruce Momjian wrote:
>
> > Ed Loehr wrote:
> >
> > > ... it is a well-known "postgresqlism"
> > > that you should consider running vacuum analyze at least nightly, possibly
> > > more frequently. [I run it hourly.]
> >
> > I think there must be something wrong with the optimiser that it's
> > "postgresqlism" that you must vacuum analyze frequently. Just as an example,
> > for Clipper (dBase compiler), it's Clipperism that you must re-index if you
> > cannot locate some records just because the indexing module screws up.
>
> Vacuum collects stats on table size on every run. Vacuum analyze every
> night is a waste unless the tables are really changing dramatically
> every day.

Agreed. My tables are changing dramatically every day under normal usage.
Ideally, vacuuming would be auto-triggered after so many
inserts/updates/deletes.

[I neglected to mention that I originally started running vacuum hourly
because it was the only way to prevent a number of bugs in 6.5.*.]

Maybe the docs need to be updated?

"We recommend that active production databases be
cleaned nightly, in order to keep statistics relatively
current."

- http://www.postgresql.org/docs/postgres/sql-vacuum.htm

Regards,
Ed Loehr