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:
Dec. 16, 2014
Filed:
Jul. 28, 2009
Grace AU, Rancho Palos Verdes, CA (US);
Rama Krishna Korlapati, El Segundo, CA (US);
Haiyan Chen, Yorktown Heights, NY (US);
Grace Au, Rancho Palos Verdes, CA (US);
Rama Krishna Korlapati, El Segundo, CA (US);
Haiyan Chen, Yorktown Heights, NY (US);
Teradata US, Inc., Dayton, OH (US);
Abstract
A method for estimating the selectivity of a database base table predicate, the cardinality of a join, and the cardinality of an aggregation. The method includes receiving a database query, the query comprising one or more query predicates and referencing one or more database tables. One or more join indexes are identified, the join index(es) defined on respective database tables referenced by the database query. The join index(es) comprises one or more join index predicates, and includes one or more join columns in its select list. The row count selected by the query predicates is calculated at least partly using the row count or statistics of the one or more join indexes. The selectivity of the base table predicate is calculated at least partly from the calculated row count. The cardinality of the join is estimated at least partly from the row count and statistics of the identified join index(es).