Device and method for generating copy of database
View Patent ↗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.
1. A device for generating a copy of an original database at a specific quiesce point in time, comprising:
a recovery start point stored with the original database;
a backup data acquisition unit for acquiring backup data of the original database output by a database management system (DBMS), before the specific point in time for use in recovering the original database, without stopping updating of the original database and while continuously operating the original database, wherein the backup data and a copy of the recovery start point are stored together in memory;
an update log acquisition unit for acquiring update logs of the original database recorded during a period between the 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 original database; and
a generation unit for generating, as the copy, a new database holding content of the original 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, 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 and to updates having not been reflected in the backup data.
2. The device according to claim 1 , further comprising a reception unit for accepting specification of the specific point in time by a user.
3. The device according to claim 1 , further comprising a recovery start point acquisition unit for acquiring the copy of the recovery start point stored in association with the backup data acquired by the backup data acquisition unit.
4. A device for generating a copy of an original database at a specific quiesce point in time, comprising:
a recovery start point stored with the original database;
a database management system (DBMS) including at least an output function for outputting backup data of the original database, temporarily stored in memory with a copy of the recovery start point, for use in recovering the original database without stopping updating of the original database and while continuously operating the original database, and a recording function for recording update logs of the original database for use in recovering the original database; and
a generation unit for generating, as the copy, a new database holding content of the original 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 the recovery start point before a time period and the specific point in time, the backup data having been output during the time period, wherein the generation unit generates the new database by updating the backup data with the update logs relating to transactions committed before the specific point in time and to updates having not been reflected in the backup data.
5. The device according to claim 4 , 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.
6. A device for generating a copy of an original database at a quiesce specific point in time, comprising:
a recovery start point stored with the original database;
a database management system (DBMS) including at least an output function for outputting backup data of the original database temporarily stored in memory with a copy of the recovery start point for use in recovering the original database without stopping updating of the original database and while continuously operating the original database, and a recording function for recording update logs of the original database for use in recovering the original 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 the 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 original 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.