Used to combine data from multiple sources.
In earlier tutorials, you worked with queries that process data from a single data stream or window. In many situations, however, you may need to correlate information from multiple data sources with a single CCL statement. For example, if you are writing an application that works with weather patterns, you might need to create a query to correlate temperature readings with wind data and to publish the combined results to a single destination. In this tutorial, you will work with queries that combine requests for information about a particular stock with information about recent stock trades.