> Von: Merlin Moncure [mmoncure@xxxxxxxxx] > Gesendet: Freitag, 20. September 2013 17:43 > > > 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 yes, a possible(?) assistance for such problems would be a new variant of regexp_split_to_table that would return two columns: - the splitted parts (as currently) - the separator matches (new) Marc -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
