PURPOSE: To reduce user's load considerably by satisfying fully the preparation for an application program with specification of a desired individual data multisegment record in addition to preparation of the newest data.

CONSTITUTION: When sales data A49 of product A is written at first and, successively, data A50 to A52 are written in respect to office X, record R2 does not exist on the data base and X1 of record R1 of office X is O in case of no storage of sales data of product A (a). When A 49 is required to be stored, it is necessary for the application program to refer to record R1 of office X before the request is accepted and data base management system makes R2 as URIAGE record, stores A49 in data region (1) and writes BEGIN (1) in region C; moreover, it writes that region (1) where data has already stored "." and regions (2) and (3) are vacant "X" (b).