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

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Andrew Dunstan <andrew(at)dunslane(dot)net>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Joel Jacobson <joel(at)compiler(dot)org>
Subject: Re: Another regexp performance improvement: skip useless paren-captures
Date: 2021-08-05 15:01:29
Message-ID: 2391720.1628175689@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> Well, I consider myself a pretty fair perl programmer, and I know
> there's a way to do that, but I never do it, and I would have had to
> look up the exact syntax. So +1 from me for anything automatic that
> avoids paying the overhead in some cases.

That's my feeling about it too --- I never really think of this
point when writing a regexp. It seems like something the engine
ought to handle gracefully, so this patch is an attempt to do so.

regards, tom lane

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Pavel Stehule 2021-08-05 15:13:54 Re: very long record lines in expanded psql output
Previous Message Platon Pronko 2021-08-05 14:50:50 Re: very long record lines in expanded psql output