Re: Size for vacuum_mem - Mailing list pgsql-general

From Shridhar Daithankar
Subject Re: Size for vacuum_mem
Date
Msg-id 3DEF4A91.28988.4E2A807@localhost
Whole thread Raw
In response to Re: Size for vacuum_mem  (Neil Conway <neilc@samurai.com>)
List pgsql-general
On 4 Dec 2002 at 19:38, Neil Conway wrote:

> > Currently a vacuum full takes 3+ hours and very soon the amount of data
> > will increase.
> Do you need to use VACUUM FULL?

Let me elaborate this statement.

1) You need vacuum full only to recover space from deleted tuples. Unless the
database has undergone major deletion somewhere 'vacuum full' might be a cannon
to kill an ant.

2) You should consider vacuuming tablewise. Vacuum is useful only for those
tables which change at a faster rate. A lookup or archive table might not need
vacuum. Just vacuum the tables which are heavily updated/deleted/inserted. And
by heavily, I mean heavily in terms of tuples. Inserting a single 200MB BLOB
and vacuuming the table might not yield any performance improvement..

 HTH

Bye
 Shridhar

--
blithwapping:    Using anything BUT a hammer to hammer a nail into the    wall, such
as shoes, lamp bases, doorstops, etc.        -- "Sniglets", Rich Hall & Friends


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