Re: Autovacuum on by default? - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Autovacuum on by default?
Date
Msg-id 20060817174334.GU318@alvh.no-ip.org
Whole thread Raw
In response to Re: Autovacuum on by default?  ("Matthew T. O'Connor" <matthew@zeut.net>)
Responses Re: Autovacuum on by default?
List pgsql-hackers
Matthew T. O'Connor wrote:
> Jim C. Nasby wrote:

> >Actually, on a table small enough for the thresholds to kick in it's
> >going to be extremely fast to vacuum anyway, and the table is probably
> >either static or changing very rapidly. I'm wondering if maybe they
> >should just default to 0?
> >  
> I assume you are suggesting that the base value be 0?  Well for one 
> thing if the table doesn't have any rows that will result in constant 
> vacuuming of that table, so it needs to be greater than 0.  For a small 
> table, say 100 rows, there usually isn'tn much performance impact if the 
> table if 50% dead space, so I think the base values you suggest are OK, 
> but they shouldn't be 0.

Actually Tom suggested some time ago that we should get rid of the base
value completely, i.e. make it 0 forever.

A row with 0 tables would not show any activity in pgstats, so it would
not be vacuumed constantly.  Only once after it's truncated.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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