the issue hunter32 was getting at is that if you are using tomcat or something then you're clearly *not* monitoring a database, you're monitoring an http server... his monitor, as yours is, is clearly http based. if your send string just so happens to call something on the server which triggers a database connection on the back end of tomcat, and that's great, but that's not monitoring the database as far as the F5 box is concerned. the recieve string should contain the entire tcp payload, so you should have the full response to play with. if you don't know what it looks like, try using curl to see the entire payload yourself. ideally you would craft a page which returns a string on the successful completion, then it's much clearer all round.
[btw when are people going to realise that putting "i" infront of anything doesn't make it look good, just a copy...?]