The following is an extension on the former post about “About Table(XMLSequence()) and XMLTable”. These examples where based on a XMLType column using CLOB storage. If you have read the “Oracle 11g – XMLType Storage Options“, then you should now know that this storage model is only performing if you had a document centric environment in mind.
Oracle’s 11g addition “XMLIndex”, will give you an solution for these kinds of environments.
The XMLIndex is a domain index, specially crafted for use in a XMLDB environment. It is a logical index with 3 components (excerpt Oracle 11g beta XMLDB Developers Guide):