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Re: Row pattern recognition

Tatsuo Ishii <ishii@postgresql.org>

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From: Tatsuo Ishii <ishii@postgresql.org>
To: assam258@gmail.com
Cc: vik@postgresfriends.org, er@xs4all.nl, jacob.champion@enterprisedb.com, david.g.johnston@gmail.com, peter@eisentraut.org, pgsql-hackers@postgresql.org
Date: 2026-02-17T06:39:22Z
Lists: pgsql-hackers 
Hi Henson,

> Anchored pattern absorption optimization
> 
>   PREFIX elements (e.g., START in "START A+ B") block absorption,
>   causing O(n^2) regression for anchored patterns.  A draft design
>   exists: track an alternate "shadow" path that skips PREFIX and
>   starts at the BODY region, enabling absorption eligibility checks
>   while the original path processes PREFIX normally.  This keeps
>   concurrent contexts bounded to PREFIX_length + 1, maintaining
>   O(n) complexity.  The design needs further refinement before
>   implementation.

What do you mean by "Anchored pattern" here? I am asking because R010
(RPR in Window clause) does not allow to use anchors (^ and $) in
PATTERN clause.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Adjust cross-version upgrade tests for seg_out() fix

  2. Rationalize error comments in partition split/merge tests

  3. Add fast path for foreign key constraint checks

  4. Fix assorted pretty-trivial memory leaks in the backend.

  5. Add temporal FOREIGN KEY contraints

  6. Add trailing commas to enum definitions

  7. Remove obsolete executor cleanup code