Re: large document multiple regex - Mailing list pgsql-general

From Jim Nasby
Subject Re: large document multiple regex
Date
Msg-id BF7F6E71-0397-4AB7-B138-9A88B98A8B99@decibel.org
Whole thread Raw
In response to large document multiple regex  ("Merlin Moncure" <mmoncure@gmail.com>)
Responses Re: large document multiple regex  ("Merlin Moncure" <mmoncure@gmail.com>)
List pgsql-general
On Jan 26, 2007, at 9:06 AM, Merlin Moncure wrote:
> I am receiving a large (300k+_ document from an external agent and
> need to reduce a few interesting bits of data out of the document on
> an insert trigger into separate fields.
>
> regex seems one way to handle this but is there any way to avoid
> rescanning the document for each regex.  One solution I am kicking
> around is some C hackery but then I lose the expressive power of
> regex.  Ideally, I need to be able to scan some text and return a
> comma delimited string of values extracted from it.  Does anybody know
> if this is possible or have any other suggestions?

Have you thought about something like ~ '(first_string|second_string|
third_string)'? Obviously your example would be more complex, but I
believe that with careful crafting, you can get regex to do a lot
without resorting to multiple passes.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)



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