I'm sure I'm just being thick, but I just can't get the following to work.

I have loaded an XSD file into an Oracle xmltype table (called xsd_table here). The xsd looks roughly like this:

Code:
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
 <xs:element name="BASE_ELEMENT">
   <xs:complexType>
    <xs:sequence>
     <xs:element name="MID_ELEMENT_A">
...