Re: Vacuum, analyze, and setting reltuples of pg_class - Mailing list pgsql-hackers

From Jim C. Nasby
Subject Re: Vacuum, analyze, and setting reltuples of pg_class
Date
Msg-id 20061213211112.GM6551@nasby.net
Whole thread Raw
In response to Re: Vacuum, analyze, and setting reltuples of pg_class  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Vacuum, analyze, and setting reltuples of pg_class  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Mon, Dec 11, 2006 at 12:08:30PM -0500, Tom Lane wrote:
> "Greg Sabino Mullane" <greg@turnstep.com> writes:
> > Short version: is it optimal for vacuum to always populate reltuples
> > with live rows + dead rows?
> 
> If we didn't do that, it would tend to encourage the use of seqscans on
> tables with lots of dead rows, which is probably a bad thing.

So then why does vacuum do that? ISTM that it makes more sense for it to
act the same as analyze and only count live rows.
-- 
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)


pgsql-hackers by date:

Previous
From: Joshua Reich
Date:
Subject: Re: EXPLAIN ANALYZE
Next
From: Tom Lane
Date:
Subject: Operator class group proposal