Collection oriented match

Abstract:

Match algorithms capable of handling large amounts of dat% without giving up expressiveness are a key requirement for successful integration of relational database systems and powerful rule-based systems. Algorithms that have been used for database rule systems have usually been unable to support large and complex rule sets, while the algorithms that have been used for rule-based expert systems do not scale welt with data. Furthermore% these algorithms do not ~ovide support for collection (or set) oriented production languages. This paper ~oposes a basic shift in the nature of match algorithms: from tuple-oriented to collectwn-oriented. A collection-oriented match algorithm matches each condition in a production with a collection of tuples and generatea collection-oriented instarrtiutwns, i.e., instantiation that have collection of tuples corresponding to each condition. This approach shows great promise for efllciently matching expressive productions against large amounts of data. In addition, it provides direct support for collection-oriented production languages. We have found that many existing tuple-oriented match algorithms can be easily rmnsfonned to their collection-oriented analogues. This paper presents the transformation of Rete to Collection Rete as an example and compares the two based on a set of benchmarks. Results presented in this paper show tha~ for large amounts of data, a relatively underoptitnized implementation of Collection Rete achieves orders of magnitude improvement in time and space over an optimized version of Rete. The results establish the feasibility of collection-oriented match for integrated database-production systems.