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:
Nov. 04, 1997
Filed:
Sep. 29, 1994
Anne Jones, Redwood City, CA (US);
Craig Zarmer, Mountain View, CA (US);
Apple Computer, Inc., Cupertino, CA (US);
Abstract
The present invention, generally speaking, provides a method of synchronizing information between a plurality of sites and a central location that solves number of potentially 'thorny' problems of distributed database systems in an elegant and efficient manner. The first issue involves sychronizing different copies of an item on machines that are not continuously linked at which each copy may be changed independently. Rather than attempting to formulate a set of synchronization policies generally applicable to all items in all instances, synchronization policies are moved from the database engine to the items themselves. The second issue involves lifetime--knowing, given a complex set of interrelationship of items, when an item may be safely deleted. This problem is addressed by providing an interested party mechanism whereby items may 'express interest' in each other. When no item is interested in a particular item, that item may safely 'go away'.