Can we specify secondary indices on get_table_rows and upper_bound/lower_bound for primary/secondary index?

At the moment we don't keep any references to the secondary indexes.

Seems that's useful when you're in the context of execution of the blockchain and you want speedy access to some rows, but in the context of an external database, we don't really care about the timings. We would like to eventually offer a full search on the rows, where you could specify through either a javascript function, or filtering through fields, and get only the rows (and columns?) you want.