Optimization of queries using relational algebraic theta-semijoin operator
Patent 6032144 Issued on February 29, 2000. Estimated Expiration Date: 
May 23, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 23, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesSystem for optimizing correlated SQL queries in a relational database using magic decorrelation Enumerating projections in SQL queries containing outer and full outer joins in the presence of inner joins Reducing query response time using tree balancing Simplification of SQL queries using generalized inference propagation and generalized transitive closure Reordering of complex SQL queries involving GROUPBYs, joins, outer joins and full outer joins Patent #: 5713015 InventorsApplicationNo. 862459 filed on 05/23/1997US Classes:707/3, Query processing (i.e., searching)707/2, Access augmentation or optimizing707/4, Query formulation, input preparation, or translation707/5Query augmenting and refining (e.g., inexact access)ExaminersPrimary: Amsbury, WayneAssistant: Channavajjala, Srirama Attorney, Agent or FirmInternational ClassG06F 017/30AbstractA collection of equivalence rules involving the multiset version of the relational algebraic theta-semijoin operator is used to generate relational algebraic expressions equivalent to a computer programming language query. These expressions may be employed as a search space which is utilized by, for example, optimizing software or software that determines the equivalency of queries. Cost formulas for the multiset version of the theta-semijoin operator may be used in computing cost estimates for the generated expressions. Based on these computed cost estimates, the least costly implementation of a complex query is determined. Thus, queries are cost-based optimized on both a local and global basis by use of the relational algebraic theta-semijoin operator.Other References
Field of SearchDATABASE OR FILE ACCESSINGAccess augmentation or optimizing Query processing (i.e., searching) Query formulation, input preparation, or translation Query augmenting and refining (e.g., inexact access) Pattern matching access DATABASE SCHEMA OR DATA STRUCTURE Generating database or data structure (e.g., via user interface) Earth science Lightning | |
