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:
Sep. 11, 1990
Filed:
Sep. 02, 1988
Akira Shibamiya, Los Altos, CA (US);
Melvin R Zimowski, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for more accurately estimating the time required to process a data base query using a selected index. A selected number of the most frequently occurring index key values (38) are collected during an index sequential scan. These most frequency occurring values are stored as percentage frequencies of occurrence in the data base system's catalog (42). Estimated access and processing times (NPAR, NPAS, NCPU) for a given query are calculated based on the stored frequencies where possible. Where the query's search criteria specify values other than the stored most frequently occurring values, those values are assumed to be uniformly distributed.