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:
Jul. 11, 1995
Filed:
Dec. 04, 1992
Andrew P Citron, Raleigh, NC (US);
James P Gray, Chapel Hill, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A transaction network in which, in appropriate cases, a transaction is allowed to complete at each node and new work to commence, before all transaction resources at the node actually complete a syncpoint operation. This desirable result is obtained without the risk of unreported database corruption. At each node in response to a prepare to commit syncpoint command from a parent node, the node in question determines if it or any of its descendant nodes can make a unilateral heuristic decision to commit or backout the transaction irrespective of whether or not the final syncpoint command is to commit or backout. Each node informs its parent node that it is reliable or unreliable. Reliable means that neither this node nor any of its descendant nodes can make a unilateral heuristic decision. Unreliable means that this node or one or more of the descendant nodes may make such a unilateral decision. If a node is reliable, the transaction is released at the node after receiving and propagating to descendant nodes the final commit or backout command and before completion or acknowledgement of completion of the commit or backout command by the node or any of its descendant nodes. If the node is unreliable, then it waits for acknowledgement of completion of the commit or backout syncpoint operation at all unreliable nodes, including itself, before releasing the transaction at the node.