Management device, database system, management method, and computer program product

A management method implemented by an information processing device and managing a data group stored in a data storage device by dividing the data group into a plurality of pages, the management method comprising:

• a generation management step of increasing a generation of the data group as time elapses;
• a page processing step of executing a page operation that is page-unitary change processing, for the data group;
• a table management step of managing 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 in which the page operation is executed last for the corresponding page;
• a data log management step of managing 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 step of managing 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
• the management method further comprises:
• in the table management step, in a case where the page operation is executed for any one of the plurality of pages, by the information processing device, updating an entry related to the page subjected to the page operation in the page table,
• in the page processing step, by the information processing device,
• securing, in a case where update processing, which is 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 updating the update target page on the secured free space, and
• adding, 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
• in the data log management step, by the information processing device,
• writing 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
• adding, 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 to which the data at the start of the current generation is written in the immediately previous operation page.

A computer program product having a non-transitory computer readable medium including programmed instructions, wherein the instructions, when executed by a computer of an information processing device configured to function as a management device that manages a data group stored in a data storage device by dividing the data group into a plurality of pages, cause the computer 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 in which the page operation is executed 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
• in a case where 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, in a case where update processing, which is 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 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, to the data log file of the current generation, 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 a CPREDO log that is the data log indicating a correspondence between the logical address and the physical address to which the data at the start of the current generation is written in the immediately previous operation page, to the data log file of the current generation.