PURPOSE: To decrease the processing time by providing an address holding condition so as to utilize the result of indexing access in the processing of the preceding inquiry when the inquiry executed immediately thereafter includes the same retrieval condition as the preceding inquiry.

CONSTITUTION: Whether or not there exists a coincidence in the object table phrase and the condition phrase between an inputted inquiry Qn and an inquiry Qm just before is inquired and the result is analyzed by an analyzing means 2. When there exists a coincident phrase, it is transmitted to the address holding means 1 and the set of corresponding record addresses is given to a set operating means. Further, the address holding means receives the address set of the record to the inquiry Qn from an index access means 3 and stored. The set operating means 4 forms the address set between the address holding means 1 and the index access means 3 based on a signal line 24, transmits the result to a record access means 5 and extracts the corresponding record from a data base file 6.