I have used this and combined it with a small autocomplete engine built on top of Redis a while back. It worked amazingly well. Users type three words and we fe

I have used this and combined it with a small autocomplete engine built on top of Redis a while back. It worked amazingly well. Users type three words and we fetch the entire list of completions from Redis, then we pass this through to Postgresql. We even built synonyms into the Redis cache, so that users who look for "car" and we have a "vehicle" in the DB, it still works. For whatever reason if the Redis instance is not up (less than 0.1% chance), then whatever the query is goes to PG's full text search backed by the trigrams. Beautiful. Granted for this to work the DB needs to be somewhat stable in size. For us, it was a list of products that rarely changes, so the Redis cache can be built on server bootstrap.