1. A method of processing streaming data, the method comprising: initializing, by a computer processor, a stream of data for a continuous query logic (CQL) operation; identifying, by the computer processor, one or more columns within the stream of data; designating, in the CQL operation, one or more of the columns to be monitored for differences in data within the columns over a time interval by applying a SELECT list expressions to a subset of the stream of data, wherein the one or more designated columns are columns of interest; applying a relation-to-stream operator to the one or more designated columns; monitoring, by the computer processor, the data within the designated columns over the time interval; determining, by the computer processor, that at least one value from at least one of the one or more designated columns has changed based on applying the relation-to stream operator to the one or more designated columns; and in response to at least one value changing, outputting the changed values from the designated columns that occur within the time interval using the CQL operation.