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:
May. 26, 1998
Filed:
Feb. 24, 1995
Gautam Bhargava, Cupertino, CA (US);
Paramesh Sampatrai Desai, San Jose, CA (US);
Piyush Goel, Monte Sereno, CA (US);
Peter Hoa, Los Altos, CA (US);
Fen-Ling Lin, San Jose, CA (US);
Balakrishna Raghavendra Iyer, San Jose, CA (US);
Jerry Mukai, San Jose, CA (US);
William Samuel Perlman, San Jose, CA (US);
Hong Sang Tie, Morgan Hill, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method, apparatus and article for manufacture for generating static, dynamic and hybrid sparse indices for use with workfiles used by SQL queries in a relational database management system. A workfile and a sparse index structure are temporarily created in the computer during execution of the query by the computer. The workfile stores intermediate relations resulting from execution of a portion of the SQL query, wherein the intermediate relations comprise sorted rows for an inner table referenced in the SQL query. The sparse index structure contains one or more entries indicating at least an approximate location for at least some of the rows in the workfile. As one or more rows from an outer table referenced in the SQL query are retrieved, the entries of the sparse index structure are searched for a closest matching entry for each retrieved row. The sorted workfile is then scanned for a row matching each retrieved row using the closest matching entry from the sparse index structure as a starting position. The sparse index structure is then updated with an entry corresponding to the row from the sorted workfile matching the retrieved row from the outer table.