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Method, System and Mechanism for Providing Better System Concurrency by Share Locks Releases in a Database System

IP.com Disclosure Number: IPCOM000022151D
Original Publication Date: 2004-Feb-27
Included in the Prior Art Database: 2004-Feb-27
Document File: 1 page(s) / 27K

Publishing Venue

IBM

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Method, System and Mechanism for Providing Better System Concurrency by Share Locks Releases in a Database System

Currently DB2 for OS/390 and z/OS keeps all the commit duration locks until commit time. For queries with cursors, even if a cursor is closed, all (share and exclusive) of its locks are kept until commit time.

Keeping the share locks from a cursor past the close cursor time has an impact on system currency. Users have to place unnecessary commit statements in their code to be able to release the share locks.

To improve system currency by allowing share locks to be released earlier than commit time. To provide a new option to adapt a new lock tracking mechanism so that the locks can be identified as candidates for early release.

This new tracking mechanism also allow DB2 for OS/390 and z/OS to provide the support for wide cursors where multiple rows can be fetched at one time and the share locks acquired on behalf of the wide cursor for the fetch can be released immediately after fetch is done.

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