Time and Relational Theory provides an in-depth description of temporal database systems, which provide special facilities for storing, querying, and updating historical and future data. Traditionally, database management systems provide little or no special support for temporal data at all. This situation is changing because:

• Cheap storage enables retention of large volumes of historical data in data warehouses
• Users are now faced with temporal data problems, and need solutions
• Temporal features have recently been incorporated into the SQL standard,...