| 摘要 |
<p>The present invention addresses the problem of allowing a client to access data without having to be aware of the storage device storing the data. A distributed database system according to the present invention comprises a plurality of storage devices (10) and a selection device (20). The plurality of storage devices (10) form two or more groups (G1, G2, G3) respectively corresponding to types of stored data. To extract required data, the selection device (20) further comprises: a first extraction unit (21) which accesses the group (G1, G2, or G3) whereupon the required data is stored, using first identification information for identifying the two or more groups (G1, G2, G3); and a second extraction unit (22) which accesses the required data using second identification information for identifying the storage site of the data within the accessed group (G1, G2, or G3).</p> |
