How can I tell Hibernate to cache lookups that aren't based on primary keys? I have the second level ehcache set up but it doesn't appear to be using the cache for a basic lookup like so: -

select * from Coupon where portfolioID = 1 and instrumentID = 1234 and couponStartDate > today

look for <natural-id>

Having thought about this a little more, I assume the cache won't be able to cope with relative queries (where you are checking for a date to be after or before another?)

nope - the cache is not queryable, that is what you use a database for ;)

(but we have actually a times (over a beer) talked about adding some kind of queryability to the caches)

btw. check out our new lucene integration in the annotaitons project....has some nice applications