Sometimes the “how to validate XML” question arises again on the OTN XMLDB Forum. A quick start would be to read up on the XMLDB FAQ Forum questions were Mark Drake demonstrates XML validation via some good examples. Another resource would be to read the Oracle XMLDB Developers Guide chapter about “Transforming and Validating XMLType Data“.
People who just like me, try to answer for fun and/or as a mind game the questions on a Oracle OTN forum, and knowing that if you do not ask for specifics, that you will have to deal with “the merry go round exercise”: With every answer given, you discover that this wasn’t the solution which was hoped for. Sometimes I am up for this because I don’t want to be bitching about: