Horton

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

Alena Rybakina <a.rybakina@postgrespro.ru>

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From: Alena Rybakina <a.rybakina@postgrespro.ru>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Pavel Borisov <pashkin.elfe@gmail.com>, Andrei Lepikhov <lepihov@gmail.com>, Alexander Lakhin <exclusion@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2025-03-28T12:31:31Z
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,

On 28.03.2025 15:23, Alena Rybakina wrote:
>
> I agree with your code in general, but to be honest, double qsort 
> confused me a little.
>
> I understood why it is needed - we need to sort the elements so that 
> they stand next to each other if they can be assigned to the same 
> group, and then sort the groups themselves according to the set 
> identifier.
>
> I may be missing something, but in the worst case we can get the 
> complexity of qsort O(n^2), right? And I saw the letter where you 
> mentioned this, but it is possible to use mergesort algorithm  instead 
> of qsort, which in the worst case gives n * O(n) complexity?
>
No, sorry, I was wrong here and it is impossible to rewrite it this way. 
I apologize, I agree with your code.

-- 
Regards,
Alena Rybakina
Postgres Professional