Patents by Inventor Kohsaku Yamahira

Kohsaku Yamahira has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Database management system, and query method and query execution program in the database management system
    Patent number: 6925462
    Abstract: The present invention relates to an optimization method in a database management system having the function of accessing external databases. Conventionally, whether functions contained in a query can be executed in external databases depends on a database management system having the functions, and therefore there has been a problem in that a database utilization method cannot apply to query optimization and query execution performance is reduced. To solve the above problem, a database management system having the function of accessing external databases is provided with an optimization step comprising the steps of: obtaining specification about whether to execute functions in a query in external databases; determining whether data referred to in a query is confined to one database; and determining whether a user specifies that the functions in the query are executed in external databases.
    Type: Grant
    Filed: January 10, 2002
    Date of Patent: August 2, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Norifumi Nishikawa, Shigekazu Inohara, Koichi Shimazaki, Kiyomi Hirohata, Kohsaku Yamahira, Shigetoshi Hayashi
  • Database management system, and query method and query execution program in the database management system
    Publication number: 20020116373
    Abstract: The present invention relates to an optimization method in a database management system having the function of accessing external databases. Conventionally, whether functions contained in a query can be executed in external databases depends on a database management system having the functions, and therefore there has been a problem in that a database utilization method cannot apply to query optimization and query execution performance is reduced. To solve the above problem, a database management system having the function of accessing external databases is provided with an optimization step comprising the steps of: obtaining specification about whether to execute functions in a query in external databases; determining whether data referred to in a query is confined to one database; and determining whether a user specifies that the functions in the query are executed in external databases.
    Type: Application
    Filed: January 10, 2002
    Publication date: August 22, 2002
    Inventors: Norifumi Nishikawa, Shigekazu Inohara, Koichi Shimazaki, Kiyomi Hirohata, Kohsaku Yamahira, Shigetoshi Hayashi