The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 12, 2010
Filed:
Jun. 10, 2004
Paul Geoffrey Brown, San Jose, CA (US);
Peter Jay Haas, San Jose, CA (US);
Ihab F. Ilyas, West Lafayette, IN (US);
Volker G. Markl, San Jose, CA (US);
Paul Geoffrey Brown, San Jose, CA (US);
Peter Jay Haas, San Jose, CA (US);
Ihab F. Ilyas, West Lafayette, IN (US);
Volker G. Markl, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method of discovering dependencies between relational database column pairs and application of discoveries to query optimization is provided. For each candidate column pair remaining after simultaneously generating column pairs, pruning pairs not satisfying specified heuristic constraints, and eliminating pairs with trivial instances of correlation, a random sample of data values is collected. A candidate column pair is tested for the existence of a soft functional dependency (FD), and if a dependency is not found, statistically tested for correlation using a robust chi-squared statistic. Column pairs for which either a soft FD or a statistical correlation exists are prioritized for recommendation to a query optimizer, based on any of: strength of dependency, degree of correlation, or adjustment factor; statistics for recommended columns pairs are tracked to improve selectivity estimates. Additionally, a dependency graph representing correlations and dependencies as edges and column pairs as nodes is provided.