Optimization of joined table expressions by extended access path selection

摘要

A method, apparatus, and article of manufacture for analyzing a query and extending an access path selection for the query, in order to optimize joined table expressions and complex join operations in the query. The extension of the access path selection occurs in two phases: (1) an access path selection router analyzes and divides the query into portions, so that the overall access path selection is divided into smaller access path selections for processing by a join enumerator; and (2) the join enumerator is provided to handle joined table expressions and complex join operators, wherein the join enumerator can be continuously enhanced as more powerful query optimization techniques become available.