On Fri, Sep 20, 2013 at 10:26 AM, Marc Mamin <M.Mamin@xxxxxxxxxxxx> wrote: > Hi, > here is a function which is about 8 x faster than the one described in the PostgreSQL SQL Tricks > ( http://postgres.cz/wiki/PostgreSQL_SQL_Tricks#Function_for_decoding_of_url_code ) > > The idea is to handle each encoded/not_encoded parts in bulk rather than spliting on each character. > > urldecode_arr: > Seq Scan on lt_referrer (actual time=1.966..17623.979 rows=65717 loops=1) > > urldecode: > Seq Scan on lt_referrer (actual time=4.846..144445.292 rows=65717 loops=1) very nice. Basically it comes down to this: all non-trivial regex replacements require decomposition of the string into an array because regexp_replace() is unable to do any kind of transformation on the string. This is a crippling limitation relative to first-class regex languages like perl; postgres string translation functions are invisible to the regex engine. I have no idea if this is fixable (I dimly recall Tom explaining why it might not be). merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
