Re: multivariate statistics v14

Tomas Vondra <tomas.vondra@2ndquadrant.com>

From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Simon Riggs <simon@2ndQuadrant.com>, Tatsuo Ishii <ishii@postgresql.org>
Cc: Robert Haas <robertmhaas@gmail.com>, David Steele <david@pgmasters.net>, Tom Lane <tgl@sss.pgh.pa.us>, Álvaro Herrera <alvherre@2ndquadrant.com>, Petr Jelinek <petr@2ndquadrant.com>, Jeff Janes <jeff.janes@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2016-04-10T18:29:16Z
Lists: pgsql-hackers
On 04/10/2016 10:25 AM, Simon Riggs wrote:
> On 9 April 2016 at 18:37, Tatsuo Ishii <ishii@postgresql.org
> <mailto:ishii@postgresql.org>> wrote:
>
>     > But I still think it wouldn't move the patch any closer to committable
>     > state, because what it really needs is review whether the catalog
>     > definition makes sense, whether it should be more like pg_statistic,
>     > and so on. Only then it makes sense to describe the catalog structure
>     > in the SGML docs, I think. That's why I added some basic SGML docs for
>     > CREATE/DROP/ALTER STATISTICS, which I expect to be rather stable, and
>     > not the catalog and other low-level stuff (which is commented heavily
>     > in the code anyway).
>
>     Without "user-level docs" (now I understand that the term means all
>     SGML docs for you), it is very hard to find a visible
>     characteristics/behavior of the patch. CREATE/DROP/ALTER STATISTICS
>     just defines a user interface, and does not help how it affects to the
>     planning. The READMEs do not help either.
>
>     In this case reviewing your code is something like reviewing a program
>     which has no specification.
>
>     That's the reason why I said before below, but it was never seriously
>     considered.
>
>
> I would likely have said this myself but didn't even get that far.
>
> Your contribution was useful and went further than anybody else's
> review, so thank you.

100% agreed. Thanks for the useful feedback.

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


Commits

  1. Collect and use multi-column dependency stats

  2. Implement SortSupport for macaddr data type

  3. Implement multivariate n-distinct coefficients

  4. Generate fmgr prototypes automatically