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:
Mar. 30, 1999
Filed:
Jan. 23, 1998
Kazutomo Ushijima, Kokubunji, JP;
Shinji Fujiwara, Sagamihara, JP;
Kazuo Masai, Yokohama, JP;
Yori Takahashi, Yokohama, JP;
Itaru Nishizawa, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A query issue processing method, a query conversion processing method, and a data control processing method are provided for enhancing the efficiency of random sampling processing for use in a database processing system. In query issue processing 2, a query including random sampling processing is issued. In query conversion processing 8, application sequences of random sampling processing and another query processing are exchanged by considering a sampling unit of the random sampling processing. Further, in record control processing 4, random access to a secondary storage device is reduced, thereby enhancing random sampling processing efficiency. Unlike the conventional query conversion processing not considering the sampling unit, the issuance of the query including random sampling processing and performing query conversion by considering the sampling unit allow random sampling to be applied also to a query including aggregation processing, thereby enhancing the efficiency of queries in a wider range. Reduction in the random access to the secondary storage device further enhances that efficiency.