US 12,222,969 B2
Management device, database system, management method, and computer program product
Masakazu Hattori, Yokohama Kanagawa (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA DIGITAL SOLUTIONS CORPORATION, Kawasaki (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA DIGITAL SOLUTIONS CORPORATION, Kawasaki (JP)
Filed on Sep. 1, 2023, as Appl. No. 18/459,472.
Application 18/459,472 is a continuation of application No. PCT/JP2021/016480, filed on Apr. 23, 2021.
Prior Publication US 2023/0409608 A1, Dec. 21, 2023
Int. Cl. G06F 16/22 (2019.01); G06F 11/14 (2006.01); G06F 16/23 (2019.01); G06F 16/28 (2019.01)
CPC G06F 16/285 (2019.01) [G06F 11/1469 (2013.01); G06F 16/2282 (2019.01); G06F 16/23 (2019.01); G06F 2201/80 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A management device that manages a data group stored in a data storage device by dividing the data group into a plurality of pages, the management device comprising:
one or more hardware processors configured to function as:
a generation management unit that increases a generation of the data group as time elapses;
a page processing unit that executes a page operation that is page-unitary change processing, for the data group;
a table management unit that manages a page table that associates, for each of the plurality of pages, a logical address, a physical address indicating a space secured for a corresponding page in the data storage device, and a last execution generation indicating the generation of executing the page operation last for the corresponding page;
a data log management unit that manages a data log file including a data log indicating a correspondence between the logical address and the physical address for each generation; and
an operation log management unit that manages an operation log file including an operation log indicating a content and an execution order of the page operation executed in a corresponding generation for each generation, wherein
when the page operation is executed for any one of the plurality of pages, the table management unit updates an entry related to the page subjected to the page operation in the page table,
the page processing unit
secures, when update processing, as one of page operations, is executed first in a current generation for any update target page among the plurality of pages, a free space in the data storage device to store data of the update target page, and updates the update target page on the secured free space, and
adds, to the data log file of the current generation, a CPUNDO log that is the data log indicating a correspondence between the logical address and the physical address indicating a position of data at start of the current generation in the update target page, and
the data log management unit
writes the data at the start of the current generation to a position indicated by the physical address of the page table in the data storage device for an immediately previous operation page subjected to the page operation in an immediately previous generation among the plurality of pages, and
adds, to the data log file of the current generation, a CPREDO log that is the data log indicating a correspondence between the logical address and the physical address with the data at the start of the current generation being written in the immediately previous operation page.