For each rule condition, several partially differentiated queries are generated that each considers changes to a single base relation or view that the condition depends on. The calculus considers both insertions and deletions. The algorithm is optimized for deferred rule condition monitoring in transactions with few updates. The calculus allows us to optimize both space and time. Space optimization is achieved since the calculus and the algorithm does not presuppose materialization of monitored conditions to find its previous state.
Time optimization is achieved through incremental evaluation techniques.
The algorithm has been implemented and a performance study is presented at the end of the paper. Inc. All rights reserved.