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A new query translation and optimization algorithm is presented. The algorithm is being implemented as the local query translation and optimization technique of Honeywell's Distributed Database Testbed System (DDTS). The algorithm translates local queries expressed in representational schemas (relational) to their equivalent internal schemas (network). The technique is new in that it does not translate each relational command in isolation, but rather attempts to find a collection of relational commands for which an optimized sequence of CODASYL DML commands can be generated. The optimization minimizes the number of disk accesses by taking advantage of the access paths available to the CODASYL local database management systems and the relationship information of the variables used in the relational commands.

Many researchers have addressed the problem of uniquely identifying updates in a distributed database system in the literature. Primitive identification schemes that generate globally unique update IDs have also been suggested. These IDs are usually used as priority among updates as well. When used as such, these schemes do not distribute priority evenly across the nodes. This paper presents a numbering scheme that generates unique update IDs and, if used as a priority scheme, is fair.