DEVICE AND METHOD FOR GENERATING COPY OF DATABASE

• US 20110093440A1
• Filed: 08/18/2010
• Published: 04/21/2011
• Est. Priority Date: 10/19/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kohno, Noriaki, Asakura, Keisuke, Boh, Ritsuko
• Granted Patent: US 8,775,386 B2
• Time in Patent Office: Days
• US Class Current: 707/685
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 2201/80 Database-specific techniques

Abstract

In a DBMS, in response to a request from application programs, a base table update function updates a base table and a recovery start point, and a log recording function records update logs for the base table. Then, at predetermined timing, a backup function outputs the content of the base table to a backup file and copies the recovery start point associated with the base table to a recovery start point. Subsequently, when a user has specified a quiesce point and the base table, a copy generation function generates a target table that is a copy of the base table at the quiesce point by updating the backup file of the specified base table with ones of the update logs from the recovery start point to the quiesce point.

Claims

1. A device for generating a copy of a database at a specific point in time, comprising:

a backup data acquisition unit for acquiring backup data of the database output by a database management system (DBMS) before the specific point in time for use in recovering the database without stopping updating of the database;

an update log acquisition unit for acquiring update logs of the database recorded during a period between a recovery start point before a time period and the specific point in time, the DBMS having output the backup data during the time period for use in recovering the database; and

a generation unit for generating, as the copy, a new database holding content of the database at the specific point in time on a basis of the backup data acquired by the backup data acquisition unit and the update logs acquired by the update log acquisition unit.

2. The device according to claim 1, wherein the generation unit generates the new database by updating the backup data acquired by the backup data acquisition unit with update logs, acquired by the update log acquisition unit, relating to transactions committed before the specific point in time.

3. The device according to claim 1, wherein the generation unit generates the new database by updating the backup data acquired by the backup data acquisition unit with update logs, acquired by the update log acquisition unit, relating to updates having not been reflected in the backup data.

4. The device according to claim 1, further comprising a reception unit for accepting specification of the specific point in time by a user.

5. The device according to claim 1, further comprising a recovery start point acquisition unit for acquiring the recovery start point stored in association with the backup data acquired by the backup data acquisition unit.

6. A device for generating a copy of a database at a specific point in time, comprising:

a database management system (DBMS) including at least an output function for outputting backup data of the database for use in recovering the database without stopping updating of the database, and a recording function for recording update logs of the database for use in recovering the database; and

a generation unit for generating, as the copy, a new database holding content of the database at the specific point in time on a basis of the backup data output by the output function of the DBMS before the specific point in time and the update logs recorded by the recording function of the DBMS during a period between a recovery start point before a time period and the specific point in time, the backup data having been output during the time period.

7. The device according to claim 6, further comprising:

a storage unit for storing a checkpoint before the time period, during which the backup data have been output, in association with the backup data output by the output function of the DBMS; and

a determination unit for determining, as the recovery start point, the checkpoint stored in the storage unit in association with the backup data.

8. A device for generating a copy of a database at a specific point in time, comprising:

a database management system (DBMS) including at least an output function for outputting backup data of the database for use in recovering the database without stopping updating of the database, and a recording function for recording update logs of the database for use in recovering the database;

a backup data acquisition unit for acquiring the backup data output by the output function of the DBMS before the specific point in time;

an update log acquisition unit for acquiring the update logs recorded by the recording function of the DBMS during a period between a recovery start point before a time period and the specific point in time, the backup data having been output during the time period; and

a generation unit for generating, as the copy, a new database holding content of the database at the specific point in time by updating the backup data acquired by the backup data acquisition unit with update logs, acquired by the update log acquisition unit, relating to transactions committed before the specific point in time and relating to updates having not been reflected in the backup data.

9. A method for generating a copy of a database at a specific point in time, the method comprising:

acquiring backup data of the database output by a database management system (DBMS) before the specific point in time for use in recovering the database without stopping updating of the database;

acquiring update logs of the database recorded during a period between a recovery start point before a time period and the specific point in time, the DBMS having output the backup data during the time period for use in recovering the database; and

generating, as the copy, a new database holding content of the database at the specific point in time on a basis of the backup data and the update logs.

10. A program product stored on a computer readable storage medium for causing a computer to function as a device for generating a copy of a database at a specific point in time, the program product causing the computer to function as:

a backup data acquisition unit for acquiring backup data of the database output by a database management system (DBMS) before the specific point in time for use in recovering the database without stopping updating of the database;

an update log acquisition unit for acquiring update logs of the database recorded during a period between a recovery start point before a time period and the specific point in time, the DBMS having output the backup data during the time period for use in recovering the database; and

a generation unit for generating, as the copy, a new database holding content of the database at the specific point in time on a basis of the backup data acquired by the backup data acquisition unit and the update logs acquired by the update log acquisition unit.