Abstract: When a complex event processing language is used in the stock analysis, fault monitoring and other industries, the demand for fine-grained query is increasing. To meet these requirements, this paper extends user-defined function that supports fine-grained data processing in a complex event processing language CEStream. Functions implement fine-grained processing by processing data one by one and function overloading. In addition, the function provides the user with the encapsulation function of the statement and improves the reusability of the language. The experimental results show that the extended function enables the language to support more fine-grained query requirements. At the same time, using the function when completing the same query requirement is basically the same as using the original statement.

Key words: complex event processing, user-defined function, event processing language