Cooperation scheme for plural work stations
First Claim
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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Accused Products
Abstract
On knowledge information processing and especially in a plan making system such as a system for generating schedule diagrams of trains and personnel, it becomes necessary to make or modify a plan by using a plurality of work stations when the plan becomes large-sized. At this time, the work stations are provided with equal plan making function. Thus, the work stations can divide planning responsibilities. Further, work stations are provided with priorities. Thus, management of competition among a plurality of work stations is facilitated and overhead caused by communication among a plurality of devices is reduced.
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Citations
20 Claims
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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:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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10. An information processing method for maintaining consistency of database copies in a processing system comprising a plurality of database operation sites that are connected to one another, one of said plurality of database operation sites having been designated a prioritized operation site having an untransmitted update request queuing area for storing database update requests until a database update is confirmed in every other one of said plurality of database operation sites, said information processing method comprising the steps of:
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inputting non duplicate database update requests at any of said database operation sites; transmitting database update requests, input at database operation sites other than said prioritized operation site, to said prioritized operation site; rejecting and deleting the update request when a contradicting request for updating the same data already exists in said untransmitted update request queuing area at said prioritized operation site; saving the non contradicting database update requests, in said update request queuing area at said prioritized operation site, as an untransmitted modification queue; changing said database of said prioritized operation site according to said database update requests; transmitting each one of said database update requests to every one of said plurality of database operation sites from said prioritized operation site; deleting individual database update requests as each of said individual database update requests is transmitted to, and the respective database update is executed in, every one of said plurality of database operation sites other than said prioritized operation site, thus serving only one update request at a time without missing succeeding update requests and without utilizing exclusive control data which includes a semaphore. - View Dependent Claims (9, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. An information processing system for use in scheduling and rescheduling and for maintaining consistency of database copies at a plurality of database operation sites that are connected to one another, said information processing system comprising:
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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 site is designated a prioritized operation site, said prioritized operation site having an original scheduling database and rescheduling database and each site other than said prioritized operation site having a database copy of said original scheduling database and rescheduling database, said prioritized operation site further having an untransmitted update request queuing area in said storage device, wherein said computer in said prioritized operation site stores, in said queuing area, the untransmitted non duplicate update request input and sent from operation sites other than said prioritized operation site, if no contradicting request for updating the same data exists in said queuing area, until said untransmitted update request is executed to update said scheduling and rescheduling databases in said prioritized operation site and said request is sent back to the operation sites other than said prioritized operation site to update the copy of said scheduling and rescheduling databases therein without utilizing exclusive control data which includes a semaphore; and input device; a display device; generating means for generating a schedule; and rescheduling means for generating a revised schedule.
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Specification