Re: pg_autovacuum parameters

Matthew T. O'Connor wrote:

> Lending, Rune wrote:
>
>> Hello all.
>>
>> I am managing a large database with lots of transactions in different
>> tables.
>> The largest tables have around 5-6 millions tuples and around
>> 50000-60000 inserts and maybe 20000 updates pr day.
>> While the smalest tables have only a few tuples and a few updates
>> /inserts pr day. In addition we have small tables with many
>> updates/inserts. So what I am saying is that there is all kinds of
>> tables and uses of tables in our database.
>> This, I think, makes it difficult to set up pg_autovacuum. I am now
>> running vacuum jobs on different tables in cron.
>>
>> What things should I consider when setting but base and threshold
>> values in pg_autovacuum? Since the running of vacuum and analyze is
>> relative to the table size, as it must be, I think it is difficult to
>> cover all tables..
>
>
> One of the biggest problems with the version of pg_autovacuum in 7.4
> contrib is that you can only specify one set of thresholds, which often
> isn't flexible enough. That said the thresholds are based on table
> since since you specify both a base value and a scaling factor so
> pg_autovacuum -v 1000 -V 1 will vacuum a table with 100 rows every 200
> updates, but will vacuum a table with 1,000,000 rows every 1,000,100
> updates.
>
>> Are there anyone who have some thoughts around this?
>
>
> Basically, you should be able to use pg_autovacuum to do most of the
> vacuuming, if there are a few tables that aren't getting vacuumed often
> enough, then you can add a vacuum command to cron for those specific
> tables.

And in the version 7.5^H^H^H8.0 ( Tom Lane docet :-) ) I think is possible
specify that thresholds per table...

Regards
Gateano Mendola