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:
Oct. 13, 2009
Filed:
Apr. 25, 2007
Thierry Cruanes, Foster City, CA (US);
Uri Shaft, Castro Valley, CA (US);
Hong Su, Foster City, CA (US);
Benoit Dageville, Foster City, CA (US);
Sunil P. Chakkappen, Foster City, CA (US);
Mohamed Zait, San Jose, CA (US);
Thierry Cruanes, Foster City, CA (US);
Uri Shaft, Castro Valley, CA (US);
Hong Su, Foster City, CA (US);
Benoit Dageville, Foster City, CA (US);
Sunil P. Chakkappen, Foster City, CA (US);
Mohamed Zait, San Jose, CA (US);
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
A method and apparatus for merging synopses to determine a database statistic, e.g., a number of distinct values (NDV), is disclosed. The merging can be used to determine an initial database statistic or to perform incremental statistics maintenance. For example, each synopsis can pertain to a different partition, such that merging the synopses generates a global statistic. When performing incremental maintenance, only those synopses whose partitions have changed need to be updated. Each synopsis contains domain values that summarize the statistic. However, the synopses may initially contain domain values that are not compatible with each other. Prior to merging the synopses the domain values in each synopsis is made compatible with the domain values in the other synopses. The adjustment is made such that each synopsis represents the same range of domain values, in one embodiment. After 'compatible synopses' are formed, the synopses are merged by taking the union of the compatible synopses.