Mind, that XML documents are not more flexible than RDBMS. You can represent any XML document in a RDBMS. You cannot represent any RDBMS in an XML document. RDBMS are (strictly spoken) relations and XML documents are trees. Relations are superior to trees, at least mathematically speaking.
Once you have set up your system in a practicable way (e.G. not needing to create a new table via SQL Queries for a new type of node, which would be a pain) SQL is far superior to XML. Anyway, cElementTree seems to be the best way to go for you now. Its performance is untopped by any other python xml library, as far as I know. -- http://mail.python.org/mailman/listinfo/python-list
