Re: [GENERAL] Idea for the statistics collector
От | Neil Conway |
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Тема | Re: [GENERAL] Idea for the statistics collector |
Дата | |
Msg-id | 20020620235538.44eb4ec2.nconway@klamath.dyndns.org обсуждение исходный текст |
Ответ на | Re: [GENERAL] Idea for the statistics collector (Bruce Momjian <pgman@candle.pha.pa.us>) |
Ответы |
Re: [GENERAL] Idea for the statistics collector
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Список | 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
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