Details on DDL Context Queries
DDL context queries are formulated in XPath
Query types:
Simple
queries (only one context parameter)
Complex
queries (join results of several simple queries)
XPath provides a powerful and flexible way to formulate
complex queries over XML
structures
Numeric and String comparison operators provided by XPath
directly operate on parameter values in the Context
Profile
Boolean
operators supported by XPath are utilized to formulate complex queries