Re: Number of occurrence of characters? - Mailing list pgsql-performance

From hubert depesz lubaczewski
Subject Re: Number of occurrence of characters?
Date
Msg-id 20090205141335.GA18324@depesz.com
Whole thread Raw
In response to Number of occurrence of characters?  (Ivan Voras <ivoras@freebsd.org>)
Responses Re: Number of occurrence of characters?
List pgsql-performance
On Thu, Feb 05, 2009 at 02:31:24PM +0100, Ivan Voras wrote:
> The problem is how to do it efficiently. I see there isn't a built-in
> function that counts character occurrences so I'd have to write it
> myself. An additional constraint is that it must be implemented with
> built-in capabilities, i.e. SQL and plpsql languages. I can do it the
> brute force way, looping over the string and processing one by one
> character with substring(), but is there a faster way?

# select length(regexp_replace('/some/string/with/slashes', '[^/]+', '', 'g'));
 length
--------
      4
(1 row)

depesz

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