Master data managing method

• US 5,765,155 A
• Filed: 09/22/1997
• Issued: 06/09/1998
• Est. Priority Date: 05/11/1994
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nakamura, Kengo
• Primary Examiner(s): AMSBURY, WAYNE P
• Application Number:
  US08/934,749
• Time in Patent Office: 260 Days
• Field of Search: 707/10, 707/200
• US Class Current: 1/1
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

In a network system in which a master computer holding the master data and a plurality of local computers are hierarchically connected through a communication line, when a terminal attached to any one of the local computers requests update for the master data, the master data is transmitted to the requesting local computer from the master computer through multiple local computers. Furthermore, in a network system in which a plurality of computers is connected through a loop communication line, and one of them holds the master data, when a terminal attached to any one of the computers requests update for the master data, the master data is transmitted to the requesting computer from a computer holding the master data.

Claims

1. A method for managing data transfer in a computer network composed of a plurality of interconnected computers, comprising:

removing data from a first computer and transferring said data to a second computer, and storing information in said first computer indicating that said data is now located in said second computer; and

removing said data from said second computer and transferring said data to a third computer via said first computer by locating said data using said information stored in said first computer.

2. A method for managing master data held by at least one of a plurality of computers interconnected to form a network, comprising the steps of:

commanding a first of said computers to remove said master data from said first computer and transfer said data to a requesting one of said computers;

if said first computer holds said master data, removing said master data from said first computer and transferring said master data to said requesting computer, storing in said first computer information indicating to which of said computers said master data has been transferred, and storing said master data in said requesting computer; and

if said first computer does not hold said master data, determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and removing said master data from said second computer and transferring said master data to said requesting computer.

3. The method of claim 2, further comprising:

commanding said first computer to process said master data;

processing said master data held by said first computer, when said first computer holds said master data; and

determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and processing said master data held by said second computer, when said first computer does not hold said master data.

4. The method of claim 2, wherein a third computer which does not hold said master data is interposed between said first and second computers, and said determining step further comprises said first computer instructing said third computer to send said master data, said third computer relaying said request to said second computer, said second computer transferring said master data to said third computer, and said third computer relaying said master data to said first computer.

5. A method for managing master data held by at least one of a plurality of computers interconnected to form a network, said computers including a top-level computer initially holding said master data and a plurality of low-level computers connected at levels lower than said top-level computer, comprising:

commanding a first of said computers to remove said master data from said first of said computers and transfer said master data to a requesting computer;

if said first computer holds said master data, removing said master data from said first computer and transferring said master data to said requesting computer, storing in said first computer information indicating to which of said computers said master data has been transferred, and storing said master data in said requesting computer;

if said first computer does not hold said master data and said information indicating to which of said computers said master data has been transferred is stored in said first computer, determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and removing said master data from said second computer and transferring said master data to said requesting computer; and

if said first computer does not hold said master data and said information indicating to which of said computers said master data has been transmitted is not stored in said first computer, determining a second of said computers which holds said master data among at least one computer connected at a level higher than said first computer, removing said master data from said second computer and transferring said master data to said requesting computer.

6. The method of claim 5, further comprising:

commanding said first computer to process said master data;

processing said master data held by said first computer, when said first computer holds said master data;

determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and processing said master data held by said second computer, when said first computer does not hold said master data and said information indicating to which of said computers said master data has been transferred is stored in said first computer; and

determining a second of said computers which holds said master data among at least one computer connected at a level higher than said first computer, and processing said master data held by said second computer, when said first computer does not hold said master data and said information indicating to which of said computers said master data has been transferred is not stored in said first computer.

7. A method for managing master data held by at least one of a plurality of computers interconnected to form a network, said network forming a loop, comprising the steps of:

commanding a first of said computers to remove said master data from said first of said computers and transfer said master data to a requesting computer;

if said first computer holds said master data, removing said master data from said first computer and transferring said master data to said requesting computer, storing in said first computer information indicating to which of said computers said master data has been transferred, and storing said master data in said requesting computer;

if said first computer does not hold said master data and said information indicating to which of said computers said master data has been transmitted is stored in said first computer, determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and removing said master data from said second computer and transferring said master data to said requesting computer; and

if when said first computer does not hold said master data and said information indicating to which of said computers said master data has been transmitted is not stored in said first computer, determining a second of said computers which holds said master data, based on information indicating to which of said computers a user possessing said master data belongs, and removing said master data from said second computer and transferring said master data to said requesting computer.

8. The method of claim 7, further comprising:

commanding said first computer to process said master data;

processing said master data held by said first computer, when said first computer holds said master data;

determining a second of said computers which holds said master data, based on said information stored in said first computer indicating to which of said computers said master data has been transferred, and processing said master data held by said second computer, when said first computer does not hold said master data and said information indicating to which of said computers said master data has been transferred is stored in said first computer; and

determining a second of said computers which holds said master data, based on said information indicating to which of said computers a user possessing said master belongs, and processing said master data held by said second computer, when said first computer does not hold said master data and said information indicating to which of said computers said master data has been transferred is not stored in said first computer.