---

In order to address the lack of XML support in Complex Event Processing (CEP) systems, we propose an approach for XML integration into a CEP engine we call EQL/XA (XML-aware event query language). As event query languages are generally SQL-based, our approach is based on the independent part of the SQL standard - XML-related Specifications (SQL/XML). EQL/XA consists of several concepts that together offer significant XML support. We introduce a data type for representing XML, an XQuery function that is able to query and construct XML data, an aggregate function that concatenates a group of XML values into a single value and last but not least, we have proposed two stream-to-stream operators that together are capable of flattening XML events into events containing only atomic EQL data types. Thus, we have significantly enhanced the expressiveness of pure EQL.

---

Martin Prodanov is a Software Engineer specialized in Complex Event Processing and In-Memory processing of streaming and pull data. After graduating from the Technical University of Darmstadt in 2011 as a M.Sc. in Computer Science, Martin is working for Software AG in the department for Intelligent Business Operations and Big Data.

---