Re: POC: GROUP BY optimization

Pavel Borisov <pashkin.elfe@gmail.com>

From: Pavel Borisov <pashkin.elfe@gmail.com>
To: Ibrar Ahmed <ibrar.ahmad@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Dmitry Dolgov <9erthalion6@gmail.com>, Teodor Sigaev <teodor@sigaev.ru>, Gavin Flower <GavinFlower@archidevsys.co.nz>, Andres Freund <andres@anarazel.de>, Michael Paquier <michael@paquier.xyz>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2021-03-05T11:49:00Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Restore preprocess_groupclause()

  2. Rename PathKeyInfo to GroupByOrdering

  3. Add invariants check to get_useful_group_keys_orderings()

  4. Fix asymmetry in setting EquivalenceClass.ec_sortref

  5. Multiple revisions to the GROUP BY reordering tests

  6. Get rid of pg_class usage in SJE regression tests

  7. Rename index "abc" in aggregates.sql

  8. Explore alternative orderings of group-by pathkeys during optimization.

  9. Generalize the common code of adding sort before processing of grouping

  10. Fix out-dated comment in preprocess_groupclause()

  11. Force parallelism in partition_aggregate

  12. Optimize order of GROUP BY keys

> Regression (stats_ext)  is failing because you forgot to drop the table
> created in a test
> case (aggregates),  It's a bit minor change so the attached patch fixes
> that issue.
>
> https://cirrus-ci.com/task/6704792446697472
>
> Thank you very much!

-- 
Best regards,
Pavel Borisov

Postgres Professional: http://postgrespro.com <http://www.postgrespro.com>