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:
Nov. 20, 2007
Filed:
Jun. 19, 2003
Nicolas Bruno, Redmond, WA (US);
Murali Krishna, Bellevue, WA (US);
Ming-chuan Wu, Redmond, WA (US);
Surajit Chaudhuri, Redmond, WA (US);
Nicolas Bruno, Redmond, WA (US);
Murali Krishna, Bellevue, WA (US);
Ming-Chuan Wu, Redmond, WA (US);
Surajit Chaudhuri, Redmond, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
A method of estimating cardinality of a join of tables using multi-column density values and additionally using coarser density values of a subset of the multi-column density attributes. In one embodiment, the subset of attributes for the coarser densities is a prefix of the set of multi-column density attributes. A number of tuples from each table that participate in the join may be estimated using densities of the subsets. The cardinality of the join can be estimated using the multi-column density for each table and the estimated number of tuples that participate in the join from each table.