DATABASE DEVICE, COMPUTER PROGRAM PRODUCT AND DATA PROCESSING METHOD

摘要

According to an embodiment, a database device includes a volatile first storing unit, a non-volatile second storing unit, an access processing unit configured to execute an operation corresponding to an access request for each of a plurality of blocks obtained by dividing data pieces, a backup processing unit configured to write data of each of the plurality of blocks at a backup time to the second storing unit, and a block management unit. The block management unit writes, under certain conditions, data of any block stored in the first storing unit to the second storing unit, and reads data of a block targeted by an access request from the second storing unit to the first storing unit. The backup processing unit writes data of a block that is not yet written to the second storing unit among the plurality of blocks.

主权项

1. A database device comprising:
a volatile first storing unit; a non-volatile second storing unit; an access processing unit configured to execute an operation corresponding to an access request for each of a plurality of blocks obtained by dividing data pieces; a backup processing unit configured to write data of each of the plurality of blocks at a backup time to the second storing unit; and a block management unit configured to, when a block targeted by an access request is not stored in the first storing unit, and the first storing unit has a free space not larger than a predetermined amount, write data of any block stored in the first storing unit to the second storing unit, and read the data of the block targeted by the access request from the second storing unit to the first storing unit, wherein the backup processing unit:
writes, sequentially for each block, data of each of the plurality of blocks at a predetermined first backup time to a first backup file in the second storing unit, on condition that the data is not yet written to the first backup file; andwrites, sequentially for each block, data of each of the plurality of blocks at a second backup time after a predetermined time from the first backup time to a second backup file in the second storing unit, on condition that the data is not yet written to the second backup file, and when an update request is made not before the first backup time and before the second backup time, and data of a block targeted by the update request is not yet written to the first backup file, the block management unit writes pre-update data of the block targeted by the update request to the first backup file.