From: | Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> |
---|---|
To: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com> |
Cc: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: multivariate statistics v14 |
Date: | 2016-03-13 21:59:38 |
Message-ID: | 1457906378.27231.10.camel@2ndquadrant.com |
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Thread: | |
Lists: | pgsql-hackers |
On Sat, 2016-03-12 at 23:30 -0800, Jeff Janes wrote:
> On Wed, Mar 9, 2016 at 9:21 AM, Tomas Vondra
> <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
> >
> > Hi,
> >
> > On Wed, 2016-03-09 at 08:45 -0800, Jeff Janes wrote:
> > >
> > > On Wed, Mar 9, 2016 at 7:02 AM, Tomas Vondra
> > > <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
> > > >
> > > > Hi,
> > > >
> > > > thanks for the feedback. Attached is v14 of the patch series,
> > > > fixing
> > > > most of the points you've raised.
> > >
> > > Hi Tomas,
> > >
> > > Applied to aa09cd242fa7e3a694a31f, I still get the seg faults in
> > > make
> > > check if I configure without --enable-cassert.
> > Ah, after disabling asserts I can reproduce it too. And the reason
> > why
> > it fails is quite simple - clauselist_selectivity modifies the
> > original
> > list of clauses, which then confuses cost_qual_eval.
> >
> > Can you try if the attached patch fixes the issue? I'll need to
> > rework a
> > bit more of the code, but let's see if this fixes the issue on your
> > machine too.
> That patch on top of v14 did fix the original problem. But I got
> another segfault:
Oh, yeah. There was an extra pfree().
Attached is v15 of the patch series, fixing this and also doing quite a
few additional improvements:
* added some basic examples into the SGML documentation
* addressing the objectaddress omissions, as pointed out by Alvaro
* support for ALTER STATISTICS ... OWNER TO / RENAME / SET SCHEMA
* significant refactoring of MCV and histogram code, particularly
serialization, deserialization and building
* reworking the functional dependencies to support more complex
dependencies, with multiple columns as 'conditions'
* the reduction using functional dependencies is also significantly
simplified (I decided to get rid of computing the transitive closure
for now - it got too complex after the multi-condition dependencies,
so I'll leave that for the future
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachment | Content-Type | Size |
---|---|---|
0008-change-how-we-apply-selectivity-to-number-of-groups-.patch | text/x-patch | 1.4 KB |
0007-multivariate-ndistinct-coefficients.patch | text/x-patch | 28.5 KB |
0006-multi-statistics-estimation.patch | text/x-patch | 98.8 KB |
0005-multivariate-histograms.patch | text/x-patch | 136.1 KB |
0004-multivariate-MCV-lists.patch | text/x-patch | 113.9 KB |
0003-clause-reduction-using-functional-dependencies.patch | text/x-patch | 69.4 KB |
0002-shared-infrastructure-and-functional-dependencies.patch | text/x-patch | 118.4 KB |
0009-fixup-of-regression-tests-plans-changes-by-group-by-.patch | text/x-patch | 5.9 KB |
0001-teach-pull_-varno-varattno-_walker-about-RestrictInf.patch | text/x-patch | 1.4 KB |
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