Re: Row pattern recognition

Tatsuo Ishii <ishii@sraoss.co.jp>

From: Tatsuo Ishii <ishii@sraoss.co.jp>

To: champion.p@gmail.com, er@xs4all.nl, vik@postgresfriends.org, pgsql-hackers@postgresql.org

Date: 2023-10-04T06:03:28Z

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 →

Add temporal FOREIGN KEY contraints
- 89f908a6d0ac 18.0 cited
Remove obsolete executor cleanup code
- d060e921ea5a 17.0 cited

Attachments

v9-0001-Row-pattern-recognition-patch-for-raw-parser.patch (text/x-patch)

> By the way, I was thinking about eliminating recusrive calls in
> pattern matching. Attached is the first cut of the implementation. In
> the attached v8 patch:
> 
> - No recursive calls anymore. search_str_set_recurse was removed.
> 
> - Instead it generates all possible pattern variable name initial
>   strings before pattern matching. Suppose we have "ab" (row 0) and
>   "ac" (row 1). "a" and "b" represents the pattern variable names
>   which are evaluated to true.  In this case it will generate "aa",
>   "ac", "ba" and "bc" and they are examined by do_pattern_match one by
>   one, which performs pattern matching.
> 
> - To implement this, an infrastructure string_set* are created. They
>   take care of set of StringInfo.
> 
> I found that the previous implementation did not search all possible
> cases. I believe the bug is fixed in v8.

The v8 patch does not apply anymore due to commit d060e921ea "Remove obsolete executor cleanup code".
So I rebased and created v9 patch. The differences from the v8 include:

- Fix bug with get_slots. It did not correctly detect the end of full frame.
- Add test case using "ROWS BETWEEN CURRENT ROW AND offset FOLLOWING".

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