From: Kenneth Marshall <ktm@rice.edu>
To: bricklen <bricklen@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: MVCC performance issue
Date: Fri, 12 Nov 2010 09:37:08 -0600
Message-ID: <20101112153708.GL14016@aart.is.rice.edu> (raw)
In-Reply-To: <AANLkTi=Js1_g3AeS7Zedu_fR2yp-USYCxoCxY0hpNeYh@mail.gmail.com>
References: <8BCBF9DB739F034B87FE7C7D30EAE55C279F054F@hqex2k.francoudi.com>
<20101112135235.GI14016@aart.is.rice.edu>
<AANLkTi=Js1_g3AeS7Zedu_fR2yp-USYCxoCxY0hpNeYh@mail.gmail.com>
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
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To: pgsql-performance@postgresql.org
Cc: ktm@rice.edu, bricklen@gmail.com
Subject: Re: MVCC performance issue
In-Reply-To: <20101112153708.GL14016@aart.is.rice.edu>
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