Le 09/02/2010 08:43, AI Rumman a écrit : > I have created a index > create index leadaddress_phone_idx on > leadaddress(regexp_replace((phone)::text, '[^0-9]*'::text, ''::text, > 'g'::text)); > > But the index is not using. > > explain select * from leadaddress where > regexp_replace(phone,'[^0-9]*','','g') like '%2159438606'; > QUERY > PLAN > -------------------------------------------------------------------------------------------------------- > Seq Scan on leadaddress (cost=100000000.00..100009699.81 rows=1 width=97) > Filter: (regexp_replace((phone)::text, '[^0-9]*'::text, ''::text, > 'g'::text) ~~ '%2159438606'::text) > > Could anyone please tell me why? I analyzed the table after index creation. > The index cannot be used if the filter is '%something' or '%somethingelse%'. I can only be used for 'this%'. -- Guillaume. http://www.postgresqlfr.org http://dalibo.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
