Re: [GENERAL] indexed regex select optimisation missing?

Bruce Momjian <maillist@candle.pha.pa.us>

From: Bruce Momjian <maillist@candle.pha.pa.us>
To: "Ross J. Reedstrom" <reedstrm@wallace.ece.rice.edu>
Cc: Stuart Woolford <stuartw@newmail.net>, pgsql-general@postgreSQL.org, Lamar Owen <lamar.owen@wgcr.org>, hackers@postgreSQL.org
Date: 1999-11-05T16:37:02Z
Lists: pgsql-hackers
> Stuart - 
> I'm forwarding a version of your last message to the hackers list, and
> to Lamar Owen, who's the keeper of the RPMs. The short verson, for those
> who haven't followed this thread over on GENERAL, is that Stuart is being
> bitten by the USE_LOCALE affect on the makeIndexable() function in the
> parser: anchored regex searches on a large table (a glossary, I believe)
> take a long time, proportional to sort position of the anchoring text:
> i.e. searching for '^zoo' is quick, '^apple' is very slow.
> 
> I seems to recall the packagers here (Lamar and Oliver) asking if defining
> USE_LOCALE for the general RPM or deb would cause any problems for other
> users, who don't need locale info. Here's a real world example.
> 
> The discussion about this was last June, and shifted focus into the
> multi-byte problem, as far as I can tell. Bruce, some version of this
> is on the TODO list, right?

I have beefed up the FAQ with a mention that locale disables regex
indexing, and have added to TODO:

	* Allow LOCALE to use indexes in regular expression searches

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026