Temporal Database

Time has always been of great interest to mankind. Much has been written about time from enormously complex philosophical manuscripts to farmers' almanacs. The most famous square in New York City is named Time's Square and a worldwide news magazine is titled Time. Not surprisingly, increasing interest in the dimension of time is being expressed by researchers working in the field of databases. The classical database is two-dimensional, and contains only data that is current, a type we will call snapshot data type. While this two-dimensional database model was adequate for older business needs, today it has become out-moded and insufficient. Today's businesses must constantly adapt to an ever-changing business environment, and their databases must support this evolving business framework. The old saying that 'time is money' is now more true than ever. More and more time-management seminars and devices are introduced everyday. As Richard Snodgrass notes "Time varying data is becoming pervasive. It has been estimated that one of every 50 lines of database application code involves a date or time value" [Snodgrass 1998]. The biggest problem in the business computer industry today, the Year 2000 problem (Y2K), is time-related. In the database field, the business solution to the lack of time support is the temporal database.