Re: autovacuum for large periodic deletes

About 5-10 million rows stay after deletion. There are a few other
tables where the daily deletion totals about 3-6 million.

Would a vacuum full/cluster affect other operations. These tables have a
24x7 high data insertion rate.

-----Original Message-----
From: Alvaro Herrera [mailto:alvherre@commandprompt.com]
Sent: Wednesday, May 17, 2006 1:36 PM
To: Sriram Dandapani
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] autovacuum for large periodic deletes

Sriram Dandapani wrote:

> Every night, a delete of about 50 million rows occurs on a table. Do
we
> need to explicitly vacuum the table or will autovacuum handle the
large
> deletes without affecting performance. I am trying to determine
whether
> or not I should completely rely on autovacuum or also tinker with
manual
> vacuums.

How many rows stay in the table after the massive deletion?  It may be
that it's best for you to issue a CLUSTER or VACUUM FULL instead of
VACUUM.  (In any case, autovacuum would vacuum the table eventually, but
maybe you can do better.)

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