Re: Notes about fixing regexes and UTF-8 (yet again) - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Notes about fixing regexes and UTF-8 (yet again)
Date
Msg-id CA+TgmoZEDfak7tSUZw8bGjGBGMTjW2tnxc+P-1sv3Ldaq3V=Hw@mail.gmail.com
Whole thread Raw
In response to Re: Notes about fixing regexes and UTF-8 (yet again)  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: Notes about fixing regexes and UTF-8 (yet again)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Fri, Feb 17, 2012 at 3:48 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> Here's a wild idea: keep the class of each codepoint in a hash table.
> Initialize it with all codepoints up to 0xFFFF. After that, whenever a
> string contains a character that's not in the hash table yet, query the
> class of that character, and add it to the hash table. Then recompile the
> whole regex and restart the matching engine.
>
> Recompiling is expensive, but if you cache the results for the session, it
> would probably be acceptable.

What if you did this ONCE and wrote the results to a file someplace?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


pgsql-hackers by date:

Previous
From: Andrew Dunstan
Date:
Subject: Re: Notes about fixing regexes and UTF-8 (yet again)
Next
From: Robert Haas
Date:
Subject: Re: MySQL search query is not executing in Postgres DB