From: Daniel Kalchev <daniel@digsys.bg>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Subject: Re: again on index usage
Date: Wed, 09 Jan 2002 18:37:49 +0200
Message-ID: <200201091637.SAA20821@dcave.digsys.bg> (raw)
In-Reply-To: <7235.1010589245@sss.pgh.pa.us>
>>>Tom Lane said:
> Hm. Okay, so the number-of-rows estimate is not too far off. I concur
> with Hiroshi's comment: the reason the indexscan is so fast must be that
> the table is clustered (physical order largely agrees with index order).
> This would obviously hold if the records were entered in order by
> ipdate; is that true?
Yes. But... do you want me to cluster it by ipaddr for example and try it
again? I understand the clustering might help with sequential scans, but why
would it help with index scans?
Daniel
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To: pgsql-hackers@postgresql.org
Cc: daniel@digsys.bg, tgl@sss.pgh.pa.us
Subject: Re: again on index usage
In-Reply-To: <200201091637.SAA20821@dcave.digsys.bg>
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