An XML schema consists of one or more XSD documents. Each of these schema documents can import or include other schema documents, resulting in a series of dependencies that must be resolved to get a complete XML schema. The XML type methods that require a schema expect a consolidated schema in which all of the dependencies have been resolved.
The consolidated schema document consists of an envelope which contains the XML representations of all the component schema documents. This consolidated schema document can then be used to construct the grammar for the intended schema.
You can use the Schema and Stylesheet Consolidation utility to consolidate your schema document before passing the schema to an XML method.
You can download sample schemas and the Schema and Stylesheet Consolidation utility from Teradata Downloads.