Comments on Tables and Columns

One can stick a comment to a COLUMN or TABLE

http://ss64.com/ora/comment.html

This is an excellent candidate to "annotate" a schema and having an automated tool process it and generate all the Entities and DAOs, using for instance the
http://download.oracle.com/javase/6/docs/api/java/sql/DatabaseMetaData.html class to introspect a schema....

One can ask: why don't you create a metamodel and generate the DDL from it, rather than trying to express everything in DDL?
Here is why: DDL is too essential to risk missing some feature by inventing a metamodel. I would rather have the DDL as the FOUNDATION of my application, rather than an artifact gnerated by some script. I think DBAs would agree with me.