The problem of efficient implementation of Horn clause logic programming as a query language for relational databases has attracted much attention in the past decade, and several methods have been proposed by researchers in the areas of Artificial Intelligence and Databases. This proposal is concerned with the efficient implementation of Horn clause programming as a query language for relational databases. The emphasis is on preserving logical completeness and performing efficiently in the presence of large numbers of facts. In this proposal, we examine a range of important issues: (1) Compile- time rule rewriting strategies, (2) Safety and effective computability of queries, (3) Parallel evaluation issues, and (4) Language issues in designing and using a logic-based query language.
