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Expired Canadian patentCanada

Database backup method

CA 1237201 A · Owner: American Telephone And Telegraph Company · Inventors: Ng, Fred K.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract A method of generating a backup copy of a database system. Modifications made to the database since the generation of a prior backup copy are summarized in a bit map on a page basis. When the next backup copy is made only modified pages are transmitted and merged with the prior copy. Plural backup passes are made. New modifications are allowed to occur to the database on all but the last pass. Any database modification made at an address that has already been examined during a pass is backed-up during the next pass. Modifications are locked out at the beginning of the last pass to allow the final generation of a consistent and complete backup copy.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted May 24, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 24, 2005.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 25, 1985
GrantedMay 24, 1988
Term endedMay 24, 2005
Patent numberCA 1237201 A
Classification (IPC)G06F12/02 +2 more

Timeline

Timeline From CIPO dates

1986198819901992199419961998200020022004Application filedJuly 25, 1985Patent grantedMay 24, 1988Term endedMay 24, 2005

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.