Just read on Sue Harpers blog that SQL Developer Datamodeller 3.0 went production. It's downloadable from its OTN-page. I'm happy to know it's a free download. End 2008 I used the beta version to model a datamodel for a project I did then. I found it a very nice tool, a good replacement for the ERD/Datamodelling capabilities of Designer. There were a few "misses, and the main ones I had were:

• Generation of pl/sql packages and functions was not possible
• Subversion support was poor: when you save a project it recreates directories to save the xml-artifacts in. Recreating directory means removal of the .svn folders, which breaks your svn working copy.

In the new features list I saw promissing statements that these should be solved now. You should be able to generate packages and functions and there is even Subversion Integration (not only support): you can see pending changes, compare models and it shoud "recognize versioned designs". Well, isn't that great?

Since it's free and since it's a really good modelling tool, I think it is a must-use on every project that uses a datamodel. Haven't used it yet? Re-engineer your ERD by importing your datamodel from the database. It gives a quick insight in the datamodel for newcomers in your project.

See also for an early adopter of Sql Developer 3.0 the SqlDeveloper OTN-page. It includes the Datamodeller.