Re: Automatic free space map filling

Alvaro Herrera <alvherre@commandprompt.com>

From: Alvaro Herrera <alvherre@commandprompt.com>
To: Csaba Nagy <nagy@ecircle-ag.com>
Cc: "Matthew T. O'Connor" <matthew@zeut.net>, Bruce Momjian <pgman@candle.pha.pa.us>, Christopher Browne <cbbrowne@acm.org>, postgres hackers <pgsql-hackers@postgresql.org>
Date: 2006-03-03T14:40:40Z
Lists: pgsql-hackers
Csaba Nagy wrote:

> Now when the queue tables get 1000 times dead space compared to their
> normal size, I get performance problems. So tweaking vacuum cost delay
> doesn't buy me anything, as not vacuum per se is the performance
> problem, it's long run time for big tables is.

So for you it would certainly help a lot to be able to vacuum the first
X pages of the big table, stop, release locks, create new transaction,
continue with the next X pages, lather, rinse, repeat.

This is perfectly doable, it only needs enough motivation from a
knowledgeable person.

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