Oracle Data Model

http://docs.oracle.com/cd/E11882_01/doc.112/e20361/toc.htm#!

Retail - http://docs.oracle.com/cd/E11882_01/doc.112/e20361/toc.htm
Communications - http://docs.oracle.com/cd/E11882_01/doc.112/e28440/toc.htm
Airlines - http://docs.oracle.com/cd/E11882_01/doc.112/e26208/toc.htm