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This paper describes the design and implementation of the Ariel DBMS and it's tightly-coupled forward-chaining rule system. The query language of Ariel is a subset of POSTQUEL, extended with a new production-rule sublanguage. Ariel supports traditional relational database query and update operations eeciently, using a System R-like query processing(More)
This paper proposes extensions to a relational database system to support the selection and execution of algorithms for shortest path search problems. An expert system can employ this extended DBMS to provide unified management of data and part of the knowledge base. Several search algorithms have been pro-totyped using the database extensions. Their(More)
† Current database trigger systems have extremely limited scalability. This paper proposes a way to develop a truly scalable trigger system. Scalability to large numbers of triggers is achieved with a trigger cache to use main memory effectively, and a memory-conserving selection predicate index based on the use of unique expression formats called(More)
Forward-chaining rule systems must test each newly asserted fact against a collection of predicates to find those rules that match the fact. Expert system rule engines use a simple combination of hashing and sequential search for this matching. We introduce an algorithm for finding the matching predicates that is more efficient than the standard algorithm(More)
Database researchers have recognized that integrating a production rules facility into a database system provides a uniform mechanism for a number of advanced database features including integrity constraint enforcement, derived data maintenance, triggers, protection, version control, and others. In addition, a database system with rule processing(More)
This paper suggests that more powerful database systems (DBMS) can be built by supporting database procedures as full-fledged database objects. In particular, allowing fields of a database to be a collection of queries in the query language of the system is shown to allow the natural expression of complex data relationships. Moreover, many of the features(More)
This paper explains the rule subsystem that is being implemented in the POSTGRES DBMS. It is novel in sev eral ways. First, it gives to users the capability of defining rules as well as data to a DBMS. Moreover, depending on the scope of each rule defined, optimization is handled differently. This leads to good performance both in the case that there are(More)