Re: Equivalent praxis to CLUSTERED INDEX? - Mailing list pgsql-performance

From Bruce Momjian
Subject Re: Equivalent praxis to CLUSTERED INDEX?
Date
Msg-id 200408280354.i7S3slb21543@candle.pha.pa.us
Whole thread Raw
In response to Re: Equivalent praxis to CLUSTERED INDEX?  (Gaetano Mendola <mendola@bigfoot.com>)
Responses Re: Equivalent praxis to CLUSTERED INDEX?  (Greg Stark <gsstark@mit.edu>)
List pgsql-performance
Gaetano Mendola wrote:
> | Right.  My point was that non-full fill is valuable for us only when
> | doing clustering, while for Oracle it is a win even in non-cluster cases
> | because of the way they update in place.
>
> Don't you think this will permit also to avoid extra disk seek and cache
> invalidation? If you are updating the row (0,1) I think is less expensive
> put the new version in (0,2) instead of thousand line far from that point.

It would, but does that outweigh the decreased I/O by having things more
densely packed?  I would think not.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

pgsql-performance by date:

Previous
From: Gaetano Mendola
Date:
Subject: Re: Equivalent praxis to CLUSTERED INDEX?
Next
From: Greg Stark
Date:
Subject: Re: Equivalent praxis to CLUSTERED INDEX?