OPTIMIZING TABLE JOIN ORDERING USING GRAPH THEORY PRIOR TO QUERY OPTIMIZATION

A method for improving the efficiency of queries in relational database management systems that use the exhaustive method of query optimization. The join structure of the query is examined prior to query optimization and tables are ordered according to graph theory. The tables in the FROM clause of the query are then reordered before query optimization. The access plan is thus developed from an already near-optimal table ordering. As a result, the number of table permutations examined during query optimization is pruned, the time to examining large numbers of table order permutations is avoided, and the optimization cost is reduced.