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Cooperation scheme for plural work stations

  • US 5,659,734 A
  • Filed: 10/10/1990
  • Issued: 08/19/1997
  • Est. Priority Date: 10/13/1989
  • Status: Expired due to Fees
First Claim
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1. An information processing system for maintaining consistency of database copies at a plurality of database operation sites that are connected to one another, said information processing system comprising:

  • said plurality of database operation sites, each having at least a computer and a storage device to store said database copies,wherein one of said database operation sites is designated a prioritized operation site, which has an untransmitted update request queuing area in said storage device, said prioritized operation site having an original database and each site having a database copy of the original database,wherein further said computer in said prioritized operation site (i) stores, in said untransmitted update request queuing area, at least one non duplicate update request input and/or sent from operation sites other than said prioritized operation site, (ii) according to said update request, updates the original database only if the update request currently being processed does not conflict with or contradict other requests stored in the untransmitted update request queuing area (iii) transmits the result of said requests to the operation sites other than said prioritized operation site, wherein the result is received in each of the operation sites other than said prioritized operation site and each of said database copies therein is updated without utilizing exclusive control data which includes a semaphore, and (iv) deletes said requests from said untransmitted update request queuing area, thus serving only one update request at a time without missing succeeding update requests;

    an input device;

    a display device;

    generating means for generating a database; and

    updating means for updating the database.

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