How to export an ER diagram from an Oracle DB? I am developing this application with an Oracle database. I haven't been documenting the data model, but now an auditor wants to have an entity relationship diagram of my database. There are many tables and creating the ERD in visio manually is out of the question.

I know Toad has Database > Export ER Diagram option, but the result is not exactly presentable because of ugly layout and difficult to edit. Do you know an alternative way which can create a presentable ER diagram? Preferably it will be nice if the resulting diagram is editable and also if the tool is free.
Have you got access to Microsoft Visio?

If you can get an ODBC connection to your Oracle DB then you can use Visio to scan the database.  It will display all the entities, relationships, etc.

Have a look at this on Stack Exchange
https://stackoverflow.com/questions/4891387/how-can-i-import-the-contents-of-an-oracle-database-into-visio-to-create-an-enti

Hope that helps