Although still in beta, version 7.5 of the PowerDesigner Suite (PD7.5) from Sybase is a stable product. As the fifth iteration of the Dolphin code rewrite, it's mature and highly functional. To examine what PD7.5 looks like, let's walk through it. I like conceptual modeling, so this is where I usually begin. I'm using PowerDesigner version 7.5.0 build 715, the second beta release of the product.

Getting Started
What you'll find in PD7.5 that's not in the 7.0 release:

• Test data generation: Complete and very functional
• Database size estimation: Also complete and accurate
• More DBMS support: The list now includes SQL Server 2000 and DB2 UDB V7
• Dimensional modeling: This used to be WarehouseArchitect but is integrated now
• Support for generated and computed columns: New feature
• Repository: Excellent advancement over the aging MetaWorks

Test Data Generation and Size Estimation
Both these functions, available in v6.1, didn't make it into v7.0. The functionality is almost exactly like v6.1, except the column property page is the Detail tab. The same idea of profiles exists with values either randomly or sequentially generated from a list or from ODBC. The test data can be generated straight to ODBC or to a file as either CSV or SQL insert statements. The generate function is available on the database menu.

Estimating the size of the database was in v6.1, but it's been enhanced to include average length and null percentages (from the test data generation) that affect the estimated database size (see Figure 1). The report is easy to read and can be printed.

Database Support
The new databases (more will be added before 7.5 is released) include:

• IBM DB2 UDB 7.x CS
• Informix SQL 9.x
• Microsoft Access 2000
• Microsoft SQL Server 2000
• NonStop SQL
• Sybase AS IQ 12.0

Dimensional Modeling
WarehouseArchitect version 6 is still available as a separate product, but since it's so similar to DataArchitect, version 7.5 is beginning to display dimensional characteristics. Now tables can be designated as "Fact" or "Dimension" with the eventual goal of including the dimensional hierarchy functionality, but that will be a later version. For now, version 7 models can be saved in version 6 format and integrated with WAMs created in WarehouseArchitect.

Generated Columns
Generated columns are supported by many DBMSs, and now PD7.5 can model them. Under the database menu the Edit DBMS item leads you to the DBMS properties dialog box. If the database supports generated columns, the Extended Attributes section will have entries (see Figure 2). This allows quite a bit of customization since you can add new attributes here. My tests showed that it does generate the correct code for DB2 v7.

The Repository and Version Control
Many design and development tools are lacking in comprehensive version control, team management, and object sharing and reuse. PD7.5 now includes a fully functional repository that provides all these points. The nice thing is that it's built in rather than being a separate module as it was in V6; it's simply the Repository tab in the browser window and the Repository menu on the toolbar (see Figure 3). Initially, you need to connect it to an existing ODBC connection (yes, it can use any valid ODBC data source, from mainframe DB2 to Microsoft Access) and initialize the tables that store the metadata. This is done from the Repository Definitions dialog found on the Repository menu (see Figure 4). You can have as many repositories as you want, from a local database to an enterprise-class server. I started by creating an ASA database and linking to it. PowerDesigner immediately prompted me to create its tables, which is automatic and doesn't take long to finish. The default account is admin, so it's a good idea to create a few user accounts. The users and groups from v6 are still here, but you have much more detailed control over user permissions.

Of course, the repository starts out empty, but it's a simple task to consolidate models (from the files or directly from the workspace). Assuming the current user has permissions, you can even take multiple copies of a model from your hard drive and make them into a single versioned model in the repository. Even better, you can consolidate many models all at once, interactively or in a batch mode, and control how conflicts (discrepancies between models in the repository and what's being consolidated) are resolved. Once you start maintaining versions, there are features in PD7.5 to make it easier. You can compare versions, branch out from the main version and merge branches back together. Using packages and version control, you can break down large projects between multiple analysts, checking out individual versions of individual packages and managing the "model library" as work is completed at different times. Since the default behavior is to version everything consolidated into the repository, you can't accidentally overwrite anything. You can always extract a previous version and work with it. With group and user security, version control and the ability to have multiple repositories, PD7.5 really gives a large data administration group true peace of mind.

Conclusion
PowerDesigner is one of the most versatile modeling tools on the market, with many features (like the integrated repository and the packages) that aren't available anywhere else. Most of the features and capabilities are intuitive, which arguably gives it the fastest learning curve on the market. Most new users are productive within the first few hours of installing PowerDesigner. Far from being a glorified graphics package, there's true theoretical accuracy and a fine degree of control that will empower serious data administrators.