Subject: Re: regex engine
From: Markus Bertheau <twanger@bluetwanger.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Jean-Luc Lachance <jllachan@sympatico.ca>,
	Keith Gallant <keith@justhosting.ca>, pgsql-sql@postgresql.org
In-Reply-To: <14659.1090776861@sss.pgh.pa.us>
References: <PDENIKIKNMLHOJKGJDLGCEPCCGAA.keith@justhosting.ca>
	<1090763779.9204.1.camel@teetnang> <4103C656.4070109@sympatico.ca>
	<1090772515.9204.3.camel@teetnang>  <14659.1090776861@sss.pgh.pa.us>
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Date: Sun, 25 Jul 2004 21:07:35 +0200
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=D0=92 =D0=92=D1=81=D0=BA, 25.07.2004, =D0=B2 19:34, Tom Lane =D0=BF=D0=B8=
=D1=88=D0=B5=D1=82:
> Markus Bertheau <twanger@bluetwanger.de> writes:
> > =D0=92 =D0=92=D1=81=D0=BA, 25.07.2004, =D0=B2 16:40, Jean-Luc Lachance =
=D0=BF=D0=B8=D1=88=D0=B5=D1=82:
> >> Better yet:
> >>=20
> >> SELECT * FROM table WHERE phrase ~ '^[0-9]';
>=20
> > Not so sure if that's better - the regex engines aren't the fastest.
>=20
> [ raised eyebrow... ]  I was under the impression that we had a pretty
> good one as of PG 7.4.  Have you tested it lately?

I wasn't trying to say that pg's regex engine was particularly slow, but
that regex engines in general are slower than an exact substring search.
If I'm mistaken here, please tell. pg's regex engine does have one
shortcoming though: it doesn't know UTF-8.

--=20
Markus Bertheau <twanger@bluetwanger.de>