An algebraic technique for deductive database system

Presents an interpreted algebraic approach to deductive database systems. Unlike the compiled approach, which separates the resolution inference from the database operations (at compile time), the interpreted approach interleaves these two operations concurrently. It is shown that this approach is simple, natural, and sometimes efficient in processing recursive queries. It also provides a better way of dealing with unsafe logical formulae, e.g. those involving logical variables. In particular, it paves the way for run-time control and optimizations of query processing. Partial solutions for the problems of termination and optimization are also proposed