Design for Success (Continued)

Extracting Designs From Legacy Databases
One immediate use was dealing with the existing databases. ER/Studio has the ability to automatically reverse-engineer a variety of ODBC databases (including DB2, Oracle, SQL Server, and Sybase) to extract the underlying design schema. That capability can save designers considerable time in analyzing and understanding the legacy databases they often must start with. This extracted design then serves as the baseline for further work and enhancements.

Of course, Capella's database designers mainly use ER/Studio to perform more "forward-engineering" design tasks. As they do, one of the main features they have found useful is ER/Studio's ability to integrate with their other tools. "We migrate from ER/Studio to MetaStage (Ascential Software's metadata management tool) and to DataStage (data transformation tool, also from Ascential)," explains Elkins. Ultimately, the data ends up in a reporting tool from Brio Software. This ability to integrate well with other tools is essential in design. Unless you're buying all your tools from a single manufacturer, you must be able to get the products to talk to one another.

Elkins has seen first-hand how making the same metadata available to developers, maintainers, and users can simplify enterprise application development; and, conversely, how metadata issues can impede development. In a previous position, Elkins was part of an effort to create a data warehouse to report the quality of certain secure transactions. The end users hated the result, and blamed the end-tool that they were using. However, the problem was that there were no plain-English descriptions attached to the cryptically named data objects. This is a simple, but telling, example of the misuse of metadata.

Capella's business systems group also uses the same ER/Studio repository that the designers use. This allows any changes to the design to ripple through the development process simply and effectively.

Elkins has been pleased with the relationship with Embarcadero. Capella has asked for certain metadata elements, and additional tags on entities and attributes. "Embarcadero has been very responsive," comments Elkins. In fact, Elkins is looking forward to trying out Embarcadero's new tool, DT/Studio, which combines database design and an ETL (extract, transform, load) tool.