On Wed, Jun 20, 2012 at 10:10 AM, Sam Z J <sammyjiang721@xxxxxxxxx> wrote: > 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 My limited understanding is that any time you need to resort to using wildcards, indices are never used, and you're falling back to using the inefficient table scan. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
