A method for providing a real time view of heterogeneous enterprise data of operational systems includes capturing streams of operational events in real time, combining the events with contextual data, and materializing a resulting view. The resulting view includes a dynamically defined view of the stream of events and provides visibility into a current state of the operational system. A view snapshot is continuously incrementally updated by a view maintenance engine as a stream of rows. The views are used to evaluate a business rule. An alert is fired when a business rule holds true. To enable the view in a view engine, a SQL string characterizing the view is parsed into a parse tree, which is normalized to form a query graph. The query graph is then optimized to obtain a query plan, which is compiled into an operator graph. Queries are executed based upon the operator graph.