Other

Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Hideaki Kasao

Kota Yamaguchi

Kazuo Masai

Kiyomi Hirohata

Keisuke Toda

A parallel database management system with a database divided into a plurality of external memory units is disclosed. A control CPU, upon receipt of a request for access to the database, decides whether the access request is for storing or searching a record. For a record storage request, the control CPU determines an external memory unit to store the record using a hash function. In the case of a record search request, on the other hand, all the external memory units are searched in parallel without using the hash function thereby to obtain the desired record. The hash function is altered upon addition of an external memory unit.

Parallel database record distribution method and parallel database management system

A parallel data base management system with a data base divided into a plurality of external memory units is disclosed. A control CPU, upon receipt of a request for access to the data base, decides whether the access request is for storing or searching a record. For a record storage request, the control CPU determines an external memory unit to store the record using a hash function. In the case of a record search request, on the other hand, all the external memory units are searched in parallel without using the hash function thereby to obtain the desired record. The hash function is altered upon addition of an external memory unit.

Parallel data base record distribution method and parallel data base management system

Parallel data base record distribution method and parallel data base

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Fujisawa, Japan

Hideaki Kasao