Re: POC: GROUP BY optimization

Tomas Vondra <tomas.vondra@enterprisedb.com>

From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Zhihong Yu <zyu@yugabyte.com>
Cc: "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>, Teodor Sigaev <teodor@sigaev.ru>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2022-03-30T23:19:24Z
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

Pushed, after going through the patch once more, running check-world
under valgrind, and updating the commit message.

Thanks to everyone who reviewed/tested this patch!

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
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