Is there a way to index in postgres for fast substring searches

Question

I have a database and want to be able to look up in a table a search that\'s something like: select * from table where column like \"abc%def%ghi\" or select * from table where c

Answer 1

If you need just to, for instance, get unique substrings in an entire table, you can create a substring index:

CREATE INDEX  i_test_sbstr ON tablename (substring(columname, 5, 3)); 
-- start at position 5, go for 3 characters

It is important that the substring() parameters in the index definition are
the same as you use in your query.

ref: http://www.postgresql.org/message-id/BANLkTinjUhGMc985QhDHKunHadM0MsGhjg@mail.gmail.com