Cache memory management apparatus having a replacement method based on the total data retrieval time and the data size

摘要

In a cache memory management device, a time measuring unit measures a time period required to obtain data from a database. The data obtained from the database is linked to the time information and both are stored in a data cache unit. If the data cache does not have sufficient room to store the data obtained from the database, a data replacement determination is made. In one embodiment, the data is replaced by referring to the total data access time. In a second embodiment, if a statistics processing unit judges that the access time and the size of each data are proportional to each other, then cache data is replaced by referring to the size information from a size calculation unit. If, however, the statistics processing unit judges that the access time and the size of each data are not proportional to each other, cache data is replaced by referring to the time information from the time measuring unit.