Computer and data read method

A computer being coupled to a storage apparatus, the storage apparatus providing a storage area to store data of a database, the storage apparatus comprising a cache memory, the storage apparatus being configured to read data into the cache memory from the storage area according to a read request, and send data from the cache memory,

• the computer comprising:
• a request receiving unit being configured to receive a data processing request as a query to the database;
• a request issuance unit being configured to determine an access usage based on the data processing request or information relating to an access usage of the data processing request, select a logical device corresponding to the determined access usage from a plurality of logical devices allocated to the storage area, and issue a read request to the selected logical device;
• and
• a query plan creation unit configured to create a query plan which is information of a database operation required for processing the received query;
• wherein the request issuance unit is configured to dynamically create a task to execute a database operation based on the created query plan, execute a plurality of dynamically created tasks in parallel, determine an access usage based on the query plan in the execution of tasks as appropriate, select a logical device corresponding to the determined access usage from a plurality of logical devices allocated to the storage area, and also issue a read request to the selected logical device.