DATA RETRIEVING DEVICE

PURPOSE:To retrieve data efficiently in a high speed by providing an associative register and substituting a page of a main storage device with a page, whose degree of relation approximates that of a page including reference data, on a basis of a degree of relation of this register. CONSTITUTION:In accordance with a request of retrieval data, it is checked whether data exists in a main storage device 2 of not by an associative register 6 of a CPU1. If data exists in the device 2, data is accessed through a cache memory 4. If data does not exist in the device, data is accessed from a secondary storage device 3 through the device 2 and the memory 4. In both cases, the response processing time of a user is used to substitute the page of the device 2 with the page, whose degree of relation approximates that of the page including reference data, on a basis of a degree of relation of the register 6. That is, the page, which is substituted for every reference, other than the reference page is substituted with a page having a high degree of relation to the reference page, and thus, data is retrieved efficiently in a high speed.