If you're using PostgreSQL you can take advantage of its full text search support. When doing so, make sure to save the text search vectors in a physical column as otherwise queries will be quite slow.
I would definitely take that option if we would use PostgreSQL, but we don't. PostgreSQL sounds like a wonderful piece of software, but they need to work on making it more accessible and user friendly. I tried getting something up and running, but given that there isn't a proper native client for Mac i gave up :(