Re: POC: GROUP BY optimization

Jonathan S. Katz <jkatz@postgresql.org>

From: "Jonathan S. Katz" <jkatz@postgresql.org>

To: Tomas Vondra <tomas.vondra@enterprisedb.com>, David Rowley <dgrowleyml@gmail.com>

Cc: Michael Paquier <michael@paquier.xyz>, Zhihong Yu <zyu@yugabyte.com>, "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: 2022-09-05T00:50:33Z

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 →

Restore preprocess_groupclause()
- 505c008ca37c 17.0 landed
Rename PathKeyInfo to GroupByOrdering
- 0c1af2c35c7b 17.0 landed
Add invariants check to get_useful_group_keys_orderings()
- 91143c03d4ca 17.0 landed
Fix asymmetry in setting EquivalenceClass.ec_sortref
- 199012a3d844 17.0 landed
Multiple revisions to the GROUP BY reordering tests
- 874d817baa16 17.0 landed
Get rid of pg_class usage in SJE regression tests
- e1b7fde418f2 17.0 landed
Rename index "abc" in aggregates.sql
- b91f91870828 17.0 landed
Explore alternative orderings of group-by pathkeys during optimization.
- 0452b461bc40 17.0 landed
Generalize the common code of adding sort before processing of grouping
- 7ab80ac1caf9 17.0 landed
Fix out-dated comment in preprocess_groupclause()
- f6c70b81802a 15.0 landed
- 78a9af1a2764 16.0 landed
Force parallelism in partition_aggregate
- 2fe6b2a806f2 16.0 landed
- 01474f56981a 15.0 landed
Optimize order of GROUP BY keys
- db0d67db2401 15.0 landed

On 9/4/22 6:14 PM, Tomas Vondra wrote:

> I've pushed the fix to 15+master. In the end I just used David's patches
> that set parallel_setup_cost to 0.

Thanks! I have closed the open item.

Jonathan