On Mon, Mar 1, 2021, at 01:53, Tom Lane wrote: >0001-fix-backref-semantics.patch >0002-backref-performance-hack.patch
I've successfully tested both patches. On HEAD the trouble-query took forever, I cancelled it after 23 minutes. HEAD (f5a5773a9dc4185414fe538525e20d8512c2ba35): SELECT regexp_matches(subject, pattern, 'g') FROM trouble; ^CCancel request sent ERROR: canceling statement due to user request Time: 1387398.764 ms (23:07.399) HEAD + 0001 + 0002: SELECT regexp_matches(subject, pattern, 'g') FROM trouble; Time: 24.943 ms Time: 22.217 ms Time: 20.250 ms Very nice! I also verified the patches gave the same result for the performance_test: SELECT is_match <> (subject ~ pattern) AS is_match_diff, captured IS DISTINCT FROM regexp_match(subject, pattern, flags) AS captured_diff, COUNT(*) FROM performance_test GROUP BY 1,2 ORDER BY 1,2 ; is_match_diff | captured_diff | count ---------------+---------------+--------- f | f | 3360068 (1 row) No notable timing differences: HEAD (f5a5773a9dc4185414fe538525e20d8512c2ba35) Time: 97016.668 ms (01:37.017) Time: 96945.567 ms (01:36.946) Time: 95261.263 ms (01:35.261) HEAD + 0001: Time: 97165.302 ms (01:37.165) Time: 96327.836 ms (01:36.328) Time: 96295.643 ms (01:36.296) HEAD + 0001 + 0002: Time: 96447.527 ms (01:36.448) Time: 94262.288 ms (01:34.262) Time: 95331.483 ms (01:35.331) /Joel
