Re: Another regexp performance improvement: skip useless paren-captures

Mark Dilger <mark(dot)dilger(at)enterprisedb(dot)com> writes:
>> On Aug 9, 2021, at 12:14 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Pushed, but while re-reading it before commit I noticed that there's
>> some more fairly low-hanging fruit in regexp_replace().

> I've been reviewing and testing this (let-regexp_replace-use-NOSUB.patch) since you sent it 4 hours ago, and I can't seem to break it. There are pre-existing problems in the regex code, but this doesn't seem to add any new breakage.

Pushed that bit, thanks for testing!

I plan to not do anything about the (()){0} bug until after the release
window, since that will need to be back-patched. That bug's gotta be
twenty years old, so while I kinda wish we'd found it a few days
earlier, waiting another 3 months won't make much difference.

regards, tom lane