Horton

Re: Additional improvements to extended statistics

Dean Rasheed <dean.a.rasheed@gmail.com>

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From: Dean Rasheed <dean.a.rasheed@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Daniel Gustafsson <daniel@yesql.se>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-11-19T09:52:04Z
Lists: pgsql-hackers 
On Wed, 18 Nov 2020 at 22:37, Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
>
> Seems fine to me, although the "_opt_ext_stats" is rather cryptic.
> AFAICS we use "_internal" for similar functions.
>

There's precedent for using "_opt_xxx" for function variants that add
an option to existing functions, but I agree that in this case it's a
bit of a mouthful. I don't think "_internal" is appropriate though,
since the clauselist function isn't internal. Perhaps using just
"_ext" would be OK.

Regards,
Dean

Commits

  1. Improve estimation of ANDs under ORs using extended statistics.

  2. Improve estimation of OR clauses using multiple extended statistics.

  3. Improve estimation of OR clauses using extended statistics.

  4. Prevent functional dependency estimates from exceeding column estimates.

  5. Fix wording of several extended stats comments

  6. Improve test coverage for multi-column MCV lists

  7. Improve test coverage for functional dependencies