I'm designing a database using a relational model that represents a hierarchical relationship.
My problem is I need to query from the bottom-up, that is, search the bottom-most table for a match, then move up a level and search for a match, and so on...

How can I organize the database efficiently?, and, since I'm using external files, how can I organize them?

thank you.

perhaps you should give us some example tables to work with?