Replication system, method and program for replicating a plurality of databases into a replica database

• US 7,519,620 B2
• Filed: 02/26/2004
• Issued: 04/14/2009
• Est. Priority Date: 09/27/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yokouchi, Hiroshi
• Primary Examiner(s): Pham; Khanh B
• Application Number:
  US10/785,990
• Publication Number:
  US 20040167936A1
• Time in Patent Office: 1,874 Days
• Field of Search: 707 1- 7, 707/100, 707/104.1, 707/200, 707/102, 709/203, 709220-221
• US Class Current: 1/1
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

Data of a plurality of master tables can be replicated in one replica table. A job to access a plurality of tables can be executed by accessing one replica table, and hence the job execution time is minimized. A correspondence is established between data using, as a key, particular data in the data of a plurality of master tables. The data field for the key is defined by the replication definition. Timing of replication for the replica table is also defined in the program to execute replication. The replication program generates, at execution thereof, the control table according to the definition and manages the operation states of a plurality of master tables and the replication state of the replica table to thereby conduct replication for the replica table at the defined timing.

Claims

1. A method for managing a plurality of master databases and a replica database generated from said plurality of master databases, comprising:

storing, as replication control information, a plurality of names of master tables of the master databases, a name of the replica database generated from said plurality of master databases by join operations based on predetermined joining keys, joining keys used in said join operations, and timing conditions setting timings at which replications of data are performed to the replica database from the master tables to correlate with each other;

in response to reception of a request for a data operation to a record stored in a first one of said master databases, storing as operation information the requested data operation to correlate identification information of an operated record with the master table name of the first master database on which the data operation request has been performed;

determining whether a processing result of the data operation request meets the timing conditions;

when the timing conditions are met, acquiring the master table name of the first master database on which said data operation request has been operated, one of said stored joining keys corresponding to said timing conditions, a second master table name of a second master database, and the replica database name to be joined by the joining key from the replication control information;

referring to said stored operation information to acquire the record subject to data operation, said record belonging to a master table of the first master database on which the data operation has been made based on the data operation request;

performing a joining processing with respect to said record subject to the data operation and said second master database to be joined using said joining key, by referring to the replication control information;

reflecting a replica database record generated by the joining processing to said replica database to implement to said replica database the data operation based on said data operation request; and

accessing the replica database in place of accessing the plurality of master databases when executing a job requiring accessing of the plurality of master databases, whereby time required for executing the job is minimized.

2. The method according to claim 1,

wherein said timing conditions include a timing at which inserted data is inserted into all of the plurality of master databases that were used to generate the replica database, and

further including a step of inserting data corresponding to said inserted data into said replica database.

3. The method according to claim 1,

wherein said timing conditions include a timing at which inserted data is inserted into the second master database of the plurality of master databases that were used to generate the replica database, and

further including a step of inserting data corresponding to said inserted data into said replica database.

4. The method according to claim 1,

wherein said timing conditions include a timing at which inserted data is inserted into at least one of the plurality of master databases that were used to generate the replica database, and

further including a step of inserting data corresponding to said inserted data into said replica database.

5. The method according to claim 1,

wherein said timing conditions include a timing at which pertinent data is deleted from one of said plurality of master databases that were used to generate the replica database, and

further including a step of deleting data corresponding to the pertinent data from said replica database.

6. The method according to claim 1,

wherein said timing conditions include a timing at which one of said master tables of said plurality of master databases that were used to generate the replica database is deleted, and

further including a step of deleting data corresponding to the deleted master table from said replica database.

7. The method according to claim 1,

wherein said timing conditions include a timing at which pertinent data is deleted from one master database of said plurality of master databases that were used to generate the replica database, and

further including a step of replacing data corresponding to the pertinent data in said replica database with an insufficient data setting value.

8. The method according to claim 1,

wherein said timing conditions include a timing at which pertinent data is deleted from all of said plurality of master databases that were used to generate the replica database, and

further including a step of deleting data corresponding to the pertinent data from said replica database.

9. The method according to claim 1,

wherein said timing conditions include a timing at which a data item is deleted from one of said plurality of master databases that were used to generate the replica database, and

further including a step of deleting data corresponding to the data item from said replica database.