Sam Z J wrote on 20.06.2012 19:10:
Hi all I'm curious how is wildcards at both ends implemented, e.g. LIKE '%str%' How efficient is it if that's the only search criteria against a large table? how much does indexing the column help and roughly how much more space is needed for the index? if the answers are too long, please point me to the relavant text =D
Since 9.1 you can speed up such a query using a trigram index. http://www.depesz.com/2011/02/19/waiting-for-9-1-faster-likeilike/ http://www.postgresonline.com/journal/archives/212-PostgreSQL-9.1-Trigrams-teaching-LIKE-and-ILIKE-new-tricks.html Another option might be to use the wildspeed extension http://www.sai.msu.su/~megera/wiki/wildspeed (never used that myself though) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
