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:
Aug. 04, 1992
Filed:
Oct. 28, 1988
Frederick P Block, Westminster, CO (US);
Norman C Chan, Louisville, CO (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In a distributed system, such as a PBX (FIG. 1), which uses a database for its operation, a master copy (22) of the database having a first format is stored at a central node (10) and cache copies (32) of database portions (24) but having a different format are stored at peripheral nodes (11-12). A change to the database is made to the master copy, is recorded in a change table (26) corresponding to the affected database portion, and is sent to affected peripheral nodes. At initialization, a boot copy (25) is made of each database portion by translating the database portion from the master database format to the cache copy format. Periodically thereafter, each boot copy is replaced with a new boot copy that reflects changes presently recorded in the corresponding change table. When the new boot copy is generated, the present change table contents are erased. When a peripheral node calls for a new cache copy (e.g., upon reboot), it is sent the corresponding boot copy and any changes presently recorded in the corresponding change table.