Horton

Re: [HACKERS] Autovacuum Improvements

Simon Riggs <simon@2ndquadrant.com>

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From: "Simon Riggs" <simon@2ndquadrant.com>
To: "Bruce Momjian" <bruce@momjian.us>
Cc: "Gregory Stark" <stark@enterprisedb.com>, "Heikki Linnakangas" <heikki@enterprisedb.com>, "Russell Smith" <mr-russ@pws.com.au>, "Darcy Buskermolen" <darcyb@commandprompt.com>, "Alvaro Herrera" <alvherre@commandprompt.com>, "Matthew T. O'Connor" <matthew@zeut.net>, "Pavan Deolasee" <pavan@enterprisedb.com>, "Christopher Browne" <cbbrowne@acm.org>, <pgsql-general@postgresql.org>, <pgsql-hackers@postgresql.org>
Date: 2007-01-22T18:42:09Z
Lists: pgsql-hackers 
On Mon, 2007-01-22 at 13:27 -0500, Bruce Momjian wrote:
> Yep, agreed on the random I/O issue.  The larger question is if you have
> a huge table, do you care to reclaim 3% of the table size, rather than
> just vacuum it when it gets to 10% dirty?  I realize the vacuum is going
> to take a lot of time, but vacuuming to relaim 3% three times seems like
> it is going to be more expensive than just vacuuming the 10% once.  And
> vacuuming to reclaim 1% ten times seems even more expensive.  The
> partial vacuum idea is starting to look like a loser to me again.

Hold that thought! Read Heikki's Piggyback VACUUM idea on new thread...

-- 
  Simon Riggs             
  EnterpriseDB   http://www.enterprisedb.com