Its not about storing the whole file into the database.
I would have a Table representing the parameteres required to construct a rule.
Now while loading the rules the application basically should read from the DB, and construct the rules, as everything required to construct the rules is avaliable in the tables.
This requirement had come up because as the rules keep changing quite frequently, we don't want to bring down the application to load a new DRL file.
Hope you understood what I want to achieve.