OPTIMIZATION OF DATABASE QUERIES FOR DATABASE SYSTEMS AND ENVIRONMENTS

As an abstract representation, a set of equivalent logical structures representative of multiple execution plans for execution of a database query can be used to optimize a database query. A logical structure can include one or more logical operators each representing multiple physical operators for executing the database query. Group and Operator Rules can be applied as rules to the set of equivalent logical structures to obtain additional equivalent logical structures and logical operator until no additional logical operators can be obtained. A set of possible implementation plans for the total number of the obtained logical operators can be obtained, for example, based on physical and/or implementation context. An optimization request can be effectively propagated through an implantation plan in a top-down manner, for example, recursively for each child of physical operators, where only new contexts are optimized, in order to generate an optimized structure, for example, in consideration of, implementation details, costs, physical properties, etc. One of the optimized structures can be selected as an optimal plan.