Re: PATCH: add support for IN and @> in functional-dependency statistics use
Tomas Vondra <tomas.vondra@2ndquadrant.com>
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Pierre Ducroquet <p.psql@pinaraf.info>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-03-17T17:05:17Z
Lists: pgsql-hackers
On Tue, Mar 17, 2020 at 04:14:26PM +0000, Dean Rasheed wrote: >On Tue, 17 Mar 2020 at 15:37, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote: >> >> On Tue, Mar 17, 2020 at 12:42:52PM +0000, Dean Rasheed wrote: >> >> >The other thing that I'm still concerned about is the possibility of >> >returning estimates with P(a,b) > P(a) or P(b). I think that such a >> >thing becomes much more likely with the new types of clause supported >> >here, because they now allow multiple values from each column, where >> >before we only allowed one. I took another look at the patch I posted >> >on the other thread, and I've convinced myself that it's correct. >> >Attached is an updated version, with some cosmetic tidying up and now >> >with some additional regression tests. >> >> Yeah, I agree that's something we need to fix. Do you plan to push the >> fix, or do you want me to do it? >> > >I can push it. Have you had a chance to review it? > Not yet, I'll take a look today. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Commits
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Prevent functional dependency estimates from exceeding column estimates.
- 87779aa47463 13.0 landed
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Recognize some OR clauses as compatible with functional dependencies
- ccaa3569f587 13.0 landed
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Use multi-variate MCV lists to estimate ScalarArrayOpExpr
- e83daa7e331e 13.0 landed
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Use functional dependencies to estimate ScalarArrayOpExpr
- 8f321bd16cdb 13.0 landed