Patent ID: 7603396

Claim:
A computer-implemented method to produce a history recording changing events in a database comprising: accessing with a computer processor a data store that includes a first record indicating first data associated with a first event, and the first record indicating a first effective time interval during which the first data is effective and the first record indicating a first time-of-creation time interval during which the first data is current with respect to the database, wherein the first effective time interval starts with a first effective-date and ends with a first end-date, and wherein the first time-of-creation interval starts with a first create-timestamp and ends with a first end-timestamp; and adjusting the data store upon an occurrence of a second event, comprising: adding a second record indicating second data associated with the second event, and the second record indicating a second effective time interval during which the second data is effective and the second record indicating a second time-of-creation time interval during which the second data is current with respect to the database, wherein the second effective time interval starts with a second effective-date and ends with a second end-date, and wherein the second time-of-creation interval starts with a second create-timestamp and ends with a second end-timestamp, if the first effective time interval starts earlier than the second effective time interval, updating the first effective time interval of the first record to be immediately preceding the second effective time interval of the second record, else setting the second effective time interval to be immediately preceding the first effective time interval.