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US 2001/0018692 A1Published application
Database system, method for forming replica of database, and computer-readable recording medium that records database replica forming program
AssigneeHitachi, Ltd.
InventorsHiroshi Suginoshita, Masayuki Kikuchi, Masao Hosoya
Life of this patent
Estimating the term…
Abstract
The preferential order to be applied in replica forming processing for the data of a plurality of types is stored when a replica of a master database that stores the data of a plurality of types is prepared. The update data of the master database is preferentially extracted according to the preferential order, and the replica is updated in the order of extraction with the extracted update data.
Claims11
A database system comprising:
- a master database to be updated;
- a replica for storing a duplicate of said master database;
- a preferential order information memory unit for holding preferential order that reflects update data of said master database on said replica for data type;
- an allocation unit for reading said update data and selectively extracting said update data according to said preferential order;
- and
- a management unit for updating said replica with said extracted update data.
3 more elements
A database system comprising:
- a master database to be updated;
- a replica for storing a duplicate of said master database;
- a preferential order acquiring unit for receiving preferential order to be applied when update data of said master database is reflected on said replica and for acquiring said preferential order;
- an allocation unit for reading said update data and selectively extracting said update data according to said preferential order;
- and
- a management unit for updating said replica with said extracted update data.
3 more elements
A database system comprising:
- a master database to be updated;
- a replica for storing the duplicate of said master database;
- a history acquiring unit for recording use history of said replica;
- and
- an updating unit for receiving update data of said master database and updating said replica with preference on a specified data type corresponding to said use history.
2 more elements
A database system comprising:
- a master database to be updated;
- a replica for storing a duplicate of said master database;
- a first control unit provided in said master database side, for selectively extracting update data according to stored preferential order of data types to be updated and for transferring it to a communication means;
- and
- a second control unit, provided in said replica side, for receiving said update data transferred from said communication means, for selectively extracting said update data according to stored preferential order of the further subdivided data type to be updated, and for updating said replica based on said extracted update data.
2 more elements
A database system comprising:
- a master database to be updated;
- a replica for storing a duplicate of said master database;
- a first control unit, provided in said master database, for transferring update data to a communication means;
- and
- a second control unit, provided in said replica side, for receiving said update data transferred from said communication means, for selectively extracting said update data according to stored preferential order of data types to be updated, and for updating said replica based on said extracted update data.
2 more elements
A database system comprising:
- a master database to be updated;
- a plurality of replicas for storing a duplicate of said master database;
- a first control unit, provided in said master database side, for selectively transferring update data;
- and
- a second control unit, provided in each of said replica side, for receiving said update data transferred, for selectively extracting said update data according to stored preferential order of data types to be updated, and for updating said replica based on said extracted update data.
2 more elements
A database system comprising:
- a master database for storing a plurality of types of data;
- a master database management unit for updating said master database in order of occurrence of an update request according to said data update request to said master database;
- an update log file for storing update log of said master database in the order of updating of said master database;
- an update log reading unit for reading out said update log from said log file;
- a data allocation unit for extracting update data in order according to preferential order determined to the plurality of data types of data from update data in said update log read by means of said update log reading unit;
- a replica for storing the duplicate of data stored in said master database;
- and
- a replica database management unit for writing said update data extracted by means of said data allocation unit in said replica in said order of extraction.
5 more elements
A method for forming a replica of a database in a system having a master database to be updated and a replica thereof, the method comprising steps of:
- holding preferential order of data types that are to be applied when update data of said master database is reflected on said replica;
- reading said update data;
- extracting said update data selectively according to said preferential order;
- and
- updating said replica with said extracted update data.
2 more elements
A method for forming a replica of a database in a system having a master database to be updated and a replica thereof, the method comprising steps of:
- extracting update data selectively according to stored preferential order of data type to be updated on said master database side;
- transferring said extracted update data to a communication means;
- receiving said update data transferred from the communication means on said replica side;
- extracting said update data selectively according to stored preferential order of further subdivided data types to be updated;
- and
- updating said replica thereby.
3 more elements
A method for forming a replica of a database in a system having a master database to be updated and a replica thereof, the method comprising steps of:
- storing data type of update data of said master database that is to be reflected preferentially on said replica;
- reading said update data;
- extracting said update data corresponding to said data type selectively;
- and
- updating said replica with said extracted update data.
2 more elements
A computer-readable recording medium having a recorded program for forming a replica of a master database to be updated, the program comprising steps of:
- holding preferential order of data types that is to be applied when update data of said master database is reflected on said replica;
- reading said update data;
- extracting said update data selectively according to said preferential order;
- and
- updating said replica with said extracted update data.
2 more elements
Dependencies are inferred from the claim text.