On 22 February 2012 23:50, Alessandro Gagliardi <alessandro(at)path(dot)com> wrote:
> I have a database where I virtually never delete and almost never do
> updates. (The updates might change in the future but for now it's okay to
> assume they never happen.) As such, it seems like it might be worth it to
> set autovacuum=off or at least make it so vacuuming hardly ever occurs.
> Actually, the latter is probably the more robust solution, though I don't
> know how to do that (hence me writing this list). I did try turning
> autovacuum off but got:
> ERROR: parameter "autovacuum" cannot be changed now
> SQL state: 55P02
> Not sure what, if anything, I can do about that.
Autovacuum is controlled by how much of a table has changed, so if a
table never changes, it never gets vacuumed (with the exceptional case
being a forced vacuum freeze to mitigate the transaction id
wrap-around issue). The settings which control this are
autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor.
Therefore it isn't necessary to disable autovacuum.
But if you are adamant about disabling it, you need to change it in
your postgresql.conf file and restart the server.
In response to
pgsql-performance by date
|Next:||From: Claudio Freire||Date: 2012-02-23 14:07:21|
|Subject: Re: Very long deletion time on a 200 GB database|
|Previous:||From: Venkat Balaji||Date: 2012-02-23 12:21:26|
|Subject: : Cost calculation for EXPLAIN output|