Re: ANALYZE sampling is too good - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: ANALYZE sampling is too good
Date
Msg-id CAM3SWZQDDA2MrFpfCpxM05Ypr0WueejQbbvVNPcXsMKr9KHWWg@mail.gmail.com
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In response to Re: ANALYZE sampling is too good  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: ANALYZE sampling is too good
Re: ANALYZE sampling is too good
List pgsql-hackers
On Tue, Dec 10, 2013 at 11:23 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> However, these things presume that we need to continue scanning most
> of the blocks of the table, which I don't think needs to be the case.
> There is a better way.

Do they? I think it's one opportunistic way of ameliorating the cost.

> Back in 2005/6, I advocated a block sampling method, as described by
> Chaudri et al (ref?)

I don't think that anyone believes that not doing block sampling is
tenable, fwiw. Clearly some type of block sampling would be preferable
for most or all purposes.


-- 
Peter Geoghegan



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