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:
Jun. 26, 2007
Filed:
Apr. 29, 2003
Bishwaranjan Bhattacharjee, Yorktown Heights, NY (US);
Leslie A. Cranston, Toronto, CA;
Matthew A. Huras, Ajax, CA;
Timothy R. Malkemus, Round Rock, TX (US);
Catherine S. Mcarthur, Uxbridge, CA;
Sriram K. Padmanabhan, Briarcliff Manor, NY (US);
Michael J. Winer, Markham, CA;
Bishwaranjan Bhattacharjee, Yorktown Heights, NY (US);
Leslie A. Cranston, Toronto, CA;
Matthew A. Huras, Ajax, CA;
Timothy R. Malkemus, Round Rock, TX (US);
Catherine S. McArthur, Uxbridge, CA;
Sriram K. Padmanabhan, Briarcliff Manor, NY (US);
Michael J. Winer, Markham, CA;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A multi-level locking hierarchy for a relational database includes a locking level applied to a multi-dimensionally clustering table, a locking level applied to blocks within the table, and a locking level applied to rows within the blocks. The hierarchy leverages the multi-dimensional clustering of the table data for efficiency and to reduce lock overhead. Data is normally locked in order of coarser to finer granularity to limit deadlock. When data of finer granularity is locked, data of coarser granularity containing the finer granularity data is also locked. Block lock durations may be employed to ensure that a block remains locked if any contained row remains locked. Block level lock attributes may facilitate detection of at least one of a concurrent scan and a row deletion within a block. Detection of the emptying of a block during a scan of the block may bar scan completion in that block.