Details
Using ERwin to Develop Bitemporal Databases
Presented by Tom Johnston
Thursday, September 22, 1:00pm EST
Session Code: ET05
Audience Level: Advanced
Track: Emerging Trends
Most implementations of bitemporal data begin with the data model. Many articles have been written on how to express bitemporal requirements in data models, and many data modelers have developed their own approaches to designing databases which include temporal data (though not usually bitemporal data). This means that the work to develop new data models is much harder, since temporal requirements are difficult to model, and the integration of temporal and non-temporal tables is even more difficult. It also means that existing data models must be modified when temporal features are retro-fitted to their databases.
One of the features of the Asserted Versioning approach to managing temporal data is that it eliminates the need to express temporal requirements in data models. Instead, temporal requirements are expressed with metadata. Since this is declarative rather than procedural work, it is much easier, and less expensive. It also results in a standard way of implementing temporal requirements which, in turn, makes the maintenance and querying of temporal databases much easier.
Based on their long experience with Erwin, Tom and Randy have developed a set of Erwin macros that automates the work of generating temporal databases. These macros reference the temporal metadata specifications associated with a non-temporal logical data model, and generate fully temporal (and bitemporal) DDL from this combination. In this presentation, Tom explains how this works.
