I can't think of any clever optimizations, unless there are some convenient constraints on the database or search query values. You could just precompute a lot

I can't think of any clever optimizations, unless there are some convenient constraints on the database or search query values. You could just precompute a lot of stuff to help you narrow down the search, but that's really not going to be feasible unless you have some constraints or some metrics on what sort of searches are being performed.