All you have to do is to connect to a database, specify which schema and which tables you want to include in your ER Model, and then just press the button. It even connects to Microsoft SQL Server 2000 database and extracts the ER Models. Pretty impressive!
I use ubuntu 8.04 and the install was easy, just unzip the downloaded file osdm-1.5.1-518-no-jre.zip to a directory and run the osdm.sh script. See instructions below.
It was about time for Oracle to come with a solution like this and for FREE, well almost. Still not clear! But I downloaded the early adopter version to try it.
You can download Oracle SQL Developer Data Modeling from: http://www.oracle.com/technology/products/database/sql_developer/files/Modeling.html
Here are the instructions to reverse engineer a schema using the tool.
1. Go to directory where you unziped the download (in my case the download osdm-1.5.1-518-no-jre.zip) like this:
2. Run the osdm.sh file like this
3. When the application starts from the menu, go to:
File > Import > DB Catalog
4. The "DB Metadata Extraction Wizard" starts.
Just follow the instructions and provide your login credentials like you would do with any other tool connecting to a database and choose the tables you want to model.
Enjoy modeling in your universe of discourse!
You can also read my other post on this topic which shows you how to create a database with OSDM here