An information processing system including a control table, which discriminates whether or not the data selected from a first external storage unit holding a large amount of data has been introduced in the main storage with reference to that control table. The data which has not been introduced in the...http://www.google.com.hk/patents/US5596707?utm_source=gb-gplus-share專利 US5596707 - Information processing system having backup/recovery facilities
