Mitsubishi Denki Kabushiki Kaisha

Takayuki Hayakawa

Mitsunori Kori

Shunichiro Nakamura

Harumi Minemura

Katsumi Shiono

Keiji Yoshimura

Rika Kashima

Manabu Michishita

Mikio Yoshimori

Takaaki Ando

Masahiro Higuchi

A file managing method includes subdividing an original file including records, each record including fields, for storing blocks, each block including fields subdivided from more than one of the records; coupling the blocks to into groups of blocks; rearranging the groups of blocks, and, after rearranging the groups of blocks, coupling the groups of blocks to each other to produce a transposed file; and accessing the fields from the transposed file, at random.

File managing method

A memory device with a redundant disk array. In order to quicken the processing of data writing into the redundant disk array, a first cache memory for accessing the redundant disk array, a second cache memory for storing old data of the first cache memory when the data of the first cache memory are renewed, and a third cache memory for storing old CK data read out of the redundant disk array when the data of the first cache memory are renewed are provided. New CK data are produced from new data for the renewal, old data stored in the second cache memory and old CK data stored in the third cache memory, and the new data for the renewal and the new CK data are stored into data storage means and CK data storage means of the redundant disk array. Since, the data read out of the cache memories are processed without reading the old data and the old CK data out of the redundant disk array, the number of accesses into the disk array at a data writing time can be reduced, and data writing can be performed at a quick speed.

Redundant disk array (raid) system utilizing separate cache memories for

Growing community of inventors

Tokyo, Japan

Takayuki Hayakawa