TIME VERSION DATA STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To support a function for viewing the state of data from an arbitrary future point by providing an effective time span, a data insertion point of time, and data indicating a record type for each record in a storage device. SOLUTION: A computer system 10 is equipped with a data base 11 and a client application 12 which accesses its data. A client gains access to the data base 11 and also acquires recording data from an archive storage device 15 by an updating function 13 and a read function 14. Each record of the data base 11 has at least one property, a time span showing that a property has an effective time span, and an insertion time indicating what time the record has been generated. Then the record has a type field indicating which of a concrete record and a digital record that possibly corrects the property value of the last concrete record or digital record the record is.