A method for transforming data formats between different database management system programs including a host computer and a disk storage device for storing data, said method comprising the steps of:
- providing, in said host computer, a database management system program, a computer program application which is executed on said database management system program, a skeleton program for instructing data format transformation and storing of a transformed data volume at a storage device connected to said host computer, information for said skeleton program to determine a data format transformation program in regard to a data volume in said disk storage device, said information being a table which sets forth corresponding relations between a plurality of data format transformation programs and addresses of said data format transformation programs in said disk storage device, and a first communication program for communication with said disk storage device;
- providing, in said disk storage device, a plurality of data format transformation programs each for executing data format transformation and a second communication program for communication with said host computer;
- obtaining, by said skeleton program, an address of a particular data format transformation program for performing data format transformation of a data volume to a transformed data volume from said table, said address of the particular data format transformation program including a Logical Unit Number (LUN) and Port Identifier (ID) indicating a particular data volume in the disk storage device where the particular data format transformation program is stored;
- sending, from said skeleton program the disk storage device, a request to cause execution of the particular data format transformation program on said disk storage device via said first communication program at the time of data format transformation to instruct data format transformation and storing, by said disk storage device, the transformed data volume within said disk storage device;
- receiving, by the particular data format transformation program, the request via said second communication program;
- and
- transforming, by the particular data format transformation program, the data volume having a data format of one database management system program on which said computer program application is executed into another data volume having the data format of another database management system program on which another computer program application is executed, said data format for said one database management system program being different from said data format of said another database management system program,
- wherein said request comprises:
- the address for specifying the particular data format transformation program,
- an address of source data,
- a size of data to be transformed, and
- a destination address at which the transformed data volume is to be stored,
- wherein said host computer retrieves the transformed data volume from the destination address.