Fujitsu Corporation

Jo Ajisawa

Minoru Yamanaka

Shuji Sekiya

Naohiro Itou

Nobuyuki Takebe

Naohiro Ito

Masashi Niwa

Hiroaki Ishimoto

A data management method includes a reference activation step, after generating a first time-series data for causing chronological relationship to be identifiable in a memory device at activation of a reference operation to a first record in a database, of referring to the first record; an update step, in response to an update request for the first record, of generating a second record corresponding to the first record in the database and updating the second record; a commit step of generating a second time-series data in the memory device at a commit operation for the updating; a reference termination step of deleting the first time-series data at completion of the reference operation; and a deletion step, if the first time-series data generated earlier than the second time-series data is not present as a result of the commit step or the reference termination step, of deleting the first record.

Apparatus and method for data management

A data presentation device with a memory storage area being used without any futility is disclosed. The data presentation device has a function of preparing on a memory and displaying on a display the first through Nth records of presentation target data group in designated sort data that is obtained when sorting all the presentation target data within a database under designated sort conditions in a form that does not store in the memory the presentation target data assured of being the (N+1)th through the last records of data, and a function of preparing on the memory and displaying on the display the ((K+1)&#xb7;(N+1))th through the ((K+2)&#xb7;N)th records of presentation sort data group in the designated sort data in a form that limits the processing target presentation sort data within the database by use of a value of a sort key within the ((K+1)&#xb7;N)th record of presentation sort data displayed on the display when instructed to display the next presentation sort data group and in a form that does not store in the memory the presentation sort data assured of being unrequired.

Data presentation device, computer readable medium and data presentation method

A database management program capable of restoring a use management book indicating allocation/non-allocation of data to individual unit storage regions, without the need to perform physical initialization at the time of reinitialization. When the database is initialized, all allocation flags provided in the use management book and indicative of allocation/non-allocation of data to the respective unit storage regions are set to a non-allocated state, and the value of an initialization counter indicative of the number of times the database has been initialized is updated. Each time data is allocated to one of the unit storage regions in the database, the allocation flag in the use management book corresponding to the data-allocated unit storage region is set to an allocated state, and the value of the initialization counter is set as an allocation-timed counter value associated with the data-allocated unit storage region.

Database management program and recording medium

In a process for managing a plurality of data items contained in a plurality of pages which are sequentially arranged in accordance with predetermined relationships, information on an amount of available space in each of the plurality of pages is stored. When a first data item is inserted into or deleted from a first page among the plurality of pages, an amount of available space in each of second and third pages is acquired based on the above information, where the second page precedes the first page in the sequential arrangement of the plurality of pages, and the third page follows the first page in the sequential arrangement. Before insertion of the first data item into the first page or after deletion of the first data item from the first page, at least one second data item contained in the first page is moved to the second page or the third page according to the amount of available space in each of the second and third pages.

Growing community of inventors

Kawasaki, Japan

Jo Ajisawa