Horton

Re: POC, WIP: OR-clause support for indexes

Alena Rybakina <lena.ribackina@yandex.ru>

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From: Alena Rybakina <lena.ribackina@yandex.ru>
To: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
Cc: Ranier Vilela <ranier.vf@gmail.com>, Marcos Pegoraro <marcos@f10.com.br>, teodor@sigaev.ru, PostgreSQL-development <pgsql-hackers@postgresql.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Peter Geoghegan <pg@bowt.ie>
Date: 2023-07-11T18:11:31Z
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. Make group_similar_or_args() reorder clause list as little as possible

  2. Allow usage of match_orclause_to_indexcol() for joins

  3. Skip not SOAP-supported indexes while transforming an OR clause into SAOP

  4. Remove the wrong assertion from match_orclause_to_indexcol()

  5. Teach bitmap path generation about transforming OR-clauses to SAOP's

  6. Transform OR-clauses to SAOP's during index matching

  7. Fix the value of or_to_any_transform_limit in postgresql.conf.sample

  8. Transform OR clauses to ANY expression

  9. MergeAttributes code deduplication

  10. SEARCH and CYCLE clauses

  11. Improve estimation of OR clauses using extended statistics.

  12. Teach btree to handle ScalarArrayOpExpr quals natively.

  13. Revise collation derivation method and expression-tree representation.

  14. Instead of trying to force WHERE clauses into CNF or DNF normal form,

Attachments

Hi!

On 11.07.2023 11:47, Andrey Lepikhov wrote:
> This patch looks much better than earlier. But it definitely needs 
> some covering with tests. As a first simple approximation, here you 
> can see the result of regression tests, where the transformation limit 
> is set to 0. See in the attachment some test changes induced by these 
> diffs.
>
Yes, I think so too. I also added some tests. I have attached an 
additional diff-5.diff where you can see the changes.
> Also, I see some impact of the transformation to other queries:
> create_view.out:
> (NOT x > z) ----> (x <= z)
> inherit.out:
> (((a)::text = 'ab'::text) OR ((a)::text = ANY ('{NULL,cd}'::text[])))
> to -
> (((a)::text = ANY ('{NULL,cd}'::text[])) OR ((a)::text = 'ab'::text))
>
> Transformations, mentioned above, are correct, of course. But it can 
> be a sign of possible unstable behavior.
>
I think it can be made more stable if we always add the existing 
transformed expressions first, and then the original ones, or vice versa. T

o do this, we will need two more lists, I think, and then we can combine 
them, where the elements of the second will be written to the end of the 
first.

But I suppose that this may not be the only unstable behavior - I 
suppose we need sorting result elements on the left side, what do you think?

-- 
Regards,
Alena Rybakina
Postgres Professional