Sorry, I used AND-statements instead of OR-statement in the example. I notices that gin is much faster than gist, but I don't know why. The query gets slow, because there are many non-stop words which appear very often in my sentences, like in 3% of all the sentences. Do you think it could be worth it to filter the words, which appears that often and declare them as stop-words. How would you split a sentence with let's say 10 non stop words to provide a performed similarity search? There's still the problem with very short sentences. An partiel index on them with the trigram search might be the solution. The pg_trgm module is far to slow for bigger setences, like you showed. I thought I'll build a few partiel indexes on the string length, to enhance the performance. Do you know some more improvements? Janek Sendrowki -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general