6 th International Workshop on Deductive Databases and Logic Programming

We discuss the semantics of complex object databases with both partial and complete tuples and sets. We redeene the notion of database to reeect the existence of partial and complete tuples and sets and study how to integrate partial information about tuples and sets spread in the database and check consistency in the meantime. We also present a deductive language RLOG II for complex objects with null/unknown and inconsistent values based on Relationlog. The main novel feature of the language is that it is the only one that supports the null extended nested relational algebra operations directly and more importantly recursively. This work provides a rm logical foundation for nested relational and complex object databases that have both partial and complete tuples and sets and solves an open problem of supporting recursion with generic null/unknown and inconsistent values in deductive databases.