Re: [GENERAL] Idea for the statistics collector - Mailing list pgsql-hackers

From Neil Conway
Subject Re: [GENERAL] Idea for the statistics collector
Date
Msg-id 20020620235538.44eb4ec2.nconway@klamath.dyndns.org
Whole thread Raw
In response to Re: [GENERAL] Idea for the statistics collector  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: [GENERAL] Idea for the statistics collector  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
On Thu, 20 Jun 2002 22:50:04 -0400 (EDT)
"Bruce Momjian" <pgman@candle.pha.pa.us> wrote:
> I have thought that some type of feedback from the executor back into
> the optimizer would be a good feature.  Not sure how to do it, but your
> idea makes sense.  It certainly could update the table statistics after
> a sequential scan.

Search the archives for a thread I started on -hackers called "self-tuning
histograms", which talks about a pretty similar idea. The technique there
applies only to histograms, and builds the histogram based *only* upon
the data provided by the executor.

Tom commented that it's probably a better idea to concentrate on more
elementary techniques, like multi-dimensional histograms, before starting
on ST histograms. I agree, and plan to look at multi-dimensional histograms
when I get some spare time.

Cheers,

Neil

-- 
Neil Conway <neilconway@rogers.com>
PGP Key ID: DB3C29FC


pgsql-hackers by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: What is wrong with hashed index usage?
Next
From: Bruce Momjian
Date:
Subject: Re: [GENERAL] Idea for the statistics collector