Stratification in shared distributed knowledge bases

There has been considerable interest in the use of stratification as a basis for ensuring several desirable properties in logic based knowledge bases and deductive databases. The author examines the problems in testing for stratifiability in large knowledge bases that are fragmented and/or distributed. They show that the usual methods for dealing with stratification in `monolithic´ knowledge bases can be extended without much difficulty to the distributed situation, using simple yet efficient algorithms for stratification checking. The benefits of these algorithms are especially significant in large systems consisting of multiple knowledge bases, each of which may have many rules and data instances