Re: multivariate statistics v14

From: Tatsuo Ishii <ishii(at)postgresql(dot)org>
To: tomas(dot)vondra(at)2ndquadrant(dot)com
Cc: jeff(dot)janes(at)gmail(dot)com, alvherre(at)2ndquadrant(dot)com, pgsql-hackers(at)postgresql(dot)org
Subject: Re: multivariate statistics v14
Date: 2016-03-23 01:53:18
Message-ID: 20160323.105318.2280241638901356703.t-ishii@sraoss.co.jp
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> The users will be able to define statistics with the limitation that
> only a single one (the one covering the most columns referenced by the
> clauses) can be used when estimating a query. Which is not perfect,
> but I think it's a valuable improvement.
>
> It might also be possible to split 0006 into smaller pieces, for
> example implementing the "non-overlapping statistics" case first and
> then extending it to more complicated cases. That might increase the
> change of getting at least some of that into 9.6 ...
>
> But considering it's not clear whether the initial chunks are likely
> to make it into 9.6 - I kinda expect a fair amount of comments from TL
> about the preceding parts, who mentioned he might look at the patch
> this week. So I'm not sure splitting 0006 into smaller pieces makes
> sense at this point.

Thanks for the explanation. I will look into patch 0001 to 0005 so
that they could get into 9.6.

In the mean time after applying patch 0001 to 0005 of v16, I get this
while compiling SGML docs.

openjade:ref/create_statistics.sgml:281:26:X: reference to non-existent ID "SQL-ALTERSTATISTICS"
openjade:ref/drop_statistics.sgml:86:26:X: reference to non-existent ID "SQL-ALTERSTATISTICS"

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

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