EP0481457A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Database system having a plurality of nodes communicating with each other via communication network
Assignee: Fujitsu Ltd
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Filing: 1991-10-16
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Granted: —
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Expires: 2011-10-16
Abstract
Abstract A database system includes a communication network (1), and a plurality of nodes (2-1 - 2-n). Each node includes a data storage device (4-1 - 4-n; l09), a management part (3-1 - 3-n; l0l) managing a status of the data stored in the data storage device, and a data storage request part (5-1 - In; 101) for generating an alternative data storage device assignment request for requesting at least one of other nodes among the plurality of nodes to store data in the data storage device of the other node via the communication network when a predetermined condition is satisfied. A determining part (l0l) receives the alternative data storage device assignment request from a request node which generates the alternative data storage device assignment request and assigns a storage area in the data storage device for storing data related to the alternative data storage device assignment request by referring to the status of the data managed by the management part when the data storage device of the other node has an enough storage capacity to store the data related to the alternative data storage device assignment request.
Inventors
- 👤 Tadamitsu Fujitsu Network Engineering Ltd. Ryu
- 👤 Gen Fujitsu Network Engineering Ltd. Kakehi
- 👤 Shigeru Fujitsu Network Engineering Ltd. Aoe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 09:04
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/20; G06F16/22; G06F16/2282
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
233 words
A database system comprising: a communication network (l); and a plurality of nodes (2-1 - 2-n; 2-00 - 2-02, 2-l0 - l-l2, 2-20 - 2-23) coupled to said communication network; characterized in that each of the nodes comprises: a data storage device (4-l - 4-n; 109) for storing data; management means (3-1 - 3-n; 101), coupled to said storage device, for managing a status of the data stored in said data storage device; data storage request means (5-1 - 5-n; 10l), said said storage device and said management means, for generating an alternative data storage device assignment request for requesting at least one of other nodes among said plurality of nodes to store data in the data storage device of said one of the other nodes via said communication network when a predetermined condition is satisfied; and determining means (101), coupled to said management means, for receiving the alternative data storage device assignment request from a request node which generates the alternative data storage device assignment request and for assigning a storage area in the data storage device for storing data related to the alternative data storage device assignment request by referring to the status of the data managed by said management means when the data storage device of said one of the other nodes has an enough storage capacity to store the data related to the alternative data storage device assignment request.
Claim 2
Dependent Claim
70 words
A database system as claimed in claim 1, characterized in that each of said nodes further comprises: response generating means (101) for generating a response signal having a node number to the request node when the storage area is assigned; and communication means (101, 111) for sending the data which should be written into the storage area assigned in the data storage device to said one of the other nodes.
Claim 3
Dependent Claim
53 words
A database system as claimed in claim 1, characterized in that said data storage request means comprises means (101, 1020) for specifying one of the other nodes and for sending, via said communication network, the alternative data storage device assignment request to a specified one of the other nodes by a poling procedure.
Claim 4
Dependent Claim
49 words
A database system as claimed in claim 1, characterized in that said data storage request means comprises means (l0l, l0l9) for sending the alternative data storage device assignment request to the communication network so that the alternative data storage device assignment request is sequentially transferred to the other nodes.
Claim 5
Dependent Claim
58 words
A database system as claimed in claim l, characterized in that said data storage request means comprises means (l0l, 1018) for simultaneously sending the alternative data storage device assignment request to the communication network by a broadcasting procedure so that the alternative data storage device assignment request is sent to the other nodes at almost the same time.
Claim 6
Dependent Claim
40 words
A database system as claimed in claim l, characterized in that said status of the data managed by said management means includes information specifying the data stored in the data storage device and information showing an amount of the data.
Claim 7
Dependent Claim
161 words
A database system as claimed in claim l, characterized in that: said plurality of nodes (2-00 - 2-02, 2-l0 - 1-12, 2-20 - 2-23) are grouped into a plurality of groups (l0-0, 10-1, 10-2), each of the groups having a provisional center node (2-00, 2-10, 2-20); said provisional center node in each of the groups comprises means (101) for managing a status of the data storage means of each of nodes in an identical group; said data storage request means of each of the other nodes comprises means (l0l) for sending the alternative data storage device assignment request to the provisional center node in the identical group; and the determining means of the provisional center node in each of the groups comprises decision means (l0l) for determining which node in the identical group can accept the alternative data storage device assignment request by referring to the status of the data storage means of each of the nodes in the identical group.
Claim 8
Dependent Claim
68 words
A database system as claimed in claim 7, characterized in that said provisional center node in each of the groups comprises means (101) for transferring the alternative data storage device assignment request to said decision means of the provisional center node in other groups when said decision means determines that there is no node in the identical group which can accept the alternative data storage device assignment request.
References Cited (Backward Citations)
No citation records indexed.
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