A method includes binding a stationed operator to a database query engine, wherein the stationed operator comprises system utilities and an open executor to execute user-supplied application logic. The method further includes receiving an unbounded input stream of input tuples by the stationed operator, the stream of input tuples comprising a succession of chunks. The method also includes applying a query defined by the application logic to each successive chunk of the input stream to produce an output packet for each such chunk, and generating an unbounded output stream comprising the output packets.