Horton

Re: POC: GROUP BY optimization

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Andrei Lepikhov <a.lepikhov@postgrespro.ru>, Tom Lane <tgl@sss.pgh.pa.us>, Richard Guo <guofenglinux@gmail.com>, Pavel Borisov <pashkin.elfe@gmail.com>, vignesh C <vignesh21@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Teodor Sigaev <teodor@sigaev.ru>, David Rowley <dgrowleyml@gmail.com>, "a.rybakina" <a.rybakina@postgrespro.ru>
Date: 2024-06-02T07:55:44Z
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

Attachments

On Fri, May 31, 2024 at 8:12 AM Alexander Korotkov <aekorotkov@gmail.com> wrote:
>
> I've revised some grammar including the sentence you've proposed.
>

-static List *groupclause_apply_groupingset(PlannerInfo *root, List *force);
+static List *preprocess_groupclause(PlannerInfo *root, List *force);

changing preprocess_groupclause the second argument
from "force" to "gset" would be more intuitive, I think.


`elog(ERROR, "Order of group-by clauses doesn't correspond incoming
sort order");`

I think this error message makes people wonder what "incoming sort order" is.
BTW, "correspond", generally people use  "correspond to".


I did some minor cosmetic changes, mainly changing foreach to foreach_node.
Please check the attachment.