A computer system, comprising a plurality of computers; and a management computer, wherein a plurality of data stores which store data obtained from a data source and having differing attributes, wherein the management computer has a request allocation unit and holds metadata management information. The request allocation unit is configured to: refer to the metadata management information to select a candidate data store based on analysis results of the data obtaining request including the time attribute of the requested data; determine whether the requested data can be obtained from the candidate data store; determine a data store to which to issue a request for obtaining the requested data; and issue the request to the determined data store.