Re: Row pattern recognition - Mailing list pgsql-hackers

From Jacob Champion
Subject Re: Row pattern recognition
Date
Msg-id CAGu=u8gcyAQAsDLp-01R21=M4bpAiGP9PZz0OyiMo5_bM30PMA@mail.gmail.com
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In response to Re: Row pattern recognition  (Tatsuo Ishii <ishii@sraoss.co.jp>)
Responses Re: Row pattern recognition
List pgsql-hackers
On Sat, Oct 21, 2023 at 7:39 PM Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
> Attached is the v10 patch. This version enhances the performance of
> pattern matching.

Nice! I've attached a couple of more stressful tests (window
partitions of 1000 rows each). Beware that the second one runs my
desktop out of memory fairly quickly with the v10 implementation.

I was able to carve out some time this week to implement a very basic
recursive NFA, which handles both the + and * qualifiers (attached).
It's not production quality -- a frame on the call stack for every row
isn't going to work -- but with only those two features, it's pretty
tiny, and it's able to run the new stress tests with no issue. If I
continue to have time, I hope to keep updating this parallel
implementation as you add features to the StringSet implementation,
and we can see how it evolves. I expect that alternation and grouping
will ratchet up the complexity.

Thanks!
--Jacob

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