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Date: Fri, 12 Nov 2010 09:37:08 -0600
From: Kenneth Marshall <ktm@rice.edu>
To: bricklen <bricklen@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: MVCC performance issue
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On Fri, Nov 12, 2010 at 07:34:36AM -0800, bricklen wrote:
> On Fri, Nov 12, 2010 at 5:52 AM, Kenneth Marshall <ktm@rice.edu> wrote:
> >
> > I cannot speak to your suggestion, but it sounds like you are not
> > vacuuming enough and a lot of the bloat/randomization would be helped
> > by making use of HOT updates in which the updates are all in the same
> > page and are reclaimed almost immediately.
> >
> > Regards,
> > Ken
> 
> IIRC, HOT only operates on non-indexed columns, so if you the tables
> are heavily indexed you won't get the full benefit of HOT. I could be
> wrong though.
> 

That is true, but if they are truly having as big a bloat problem
as the message indicated, it would be worth designing the schema
to leverage HOT for the very frequent updates.

Cheers,
Ken