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Re: Equivalent praxis to CLUSTERED INDEX?

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Gaetano Mendola <mendola(at)bigfoot(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>,"pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Equivalent praxis to CLUSTERED INDEX?
Date: 2004-08-28 03:54:47
Message-ID: 200408280354.i7S3slb21543@candle.pha.pa.us (view raw or flat)
Thread:
Lists: 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(at)candle(dot)pha(dot)pa(dot)us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
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Subject: Re: Equivalent praxis to CLUSTERED INDEX?
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