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:
Dec. 06, 1994
Filed:
Dec. 09, 1993
Kathryn H Britton, Chapel Hill, NC (US);
Andrew P Citron, Raleigh, NC (US);
Bruce G Lindsay, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of managing unit-of-work identifiers in a chained distributed database transaction system. The system has a plurality of processing nodes which are logically connected to form a tree. Normally, each node automatically increments its present identifier at the end of processing each transaction to derive the next transaction identifier. However, in response to a failure condition which results in a severed tree, the distributed database that now reside in the first and second subtrees that result from the severance are forced to consistent states. The transaction identifier is incremented in each of the nodes of the first subtree. Transaction work in the first subtree then proceeds with the incremented identifier. The second subtree is dismantled. In response to a nonfailure condition which results in a severed tree, the distributed database in the first and second subtrees that result from the nonfailure severance is committed to a permanent state. The transaction identifier in each of the nodes of the first subtree is incremented. Transaction work in the first subtree then proceeds with the incremented identifier. A new transaction identifier is generated and propagated to all nodes of the second subtree. Transaction work in the second subtree then proceeds with the new identifier.