Tom Lane escribió:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > Tom Lane escribi�:
> >> I believe the interpretation of autovacuum_naptime is that it should
> >> examine each database that often, ie once a minute by default. So
> >> it's got more than 30 databases per second to look through.
>
> > Note that this is correct in 8.1 and 8.2 but not 8.3 onwards.
>
> Oh? The current documentation still defines the variable thusly:
>
> Specifies the minimum delay between autovacuum runs on any given
> database. In each round the daemon examines the database and
> issues VACUUM and ANALYZE commands as needed for tables in that
> database.
Sorry, it's the other way around actually -- correct for 8.3 onwards,
wrong for 8.1 and 8.2. In the earlier versions, it would do one run in
a chosen database, sleep during "naptime", then do another run.
> I suppose the use of "minimum" means that this is not technically
> incorrect, but it's sure not very helpful if there is some other
> rule involved that causes it to not behave as I said. (And if there
> is some other rule, what is that?)
The word "minimum" is there because it's possible that all workers are
busy with some other database(s).
> Please improve the docs.
I'll see about that.
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support
