Two recent trends—the plummeting cost of storage and the widespread adoption of data warehouse technology—have led to an increasing interest in temporal databases. Indeed, the idea of maintaining and processing historical data has become not just a goal but also a reality for many organizations. Consequently, the ability to deal properly with the time dimension in databases has become an increasingly important practical problem. And today’s mainstream DBMS products are beginning to include features that are specifically designed to help with this important requirement—though it has to be said too that the support currently found in those products falls a long way short of the theoretical ideal.
This Master Class video describes and explains that theoretical ideal—which, interestingly, is 100 percent consistent with the classical relational model—in depth. It also discusses, in depth, the new temporal support to be found in the SQL standard (“SQL:2011”). This video includes five major parts: