1. A non-transitory computer-readable medium storing instructions for executing a stream data processing method that receives stream data input information as primary information and generates secondary information by acquiring primary information within a predetermined period from among the received primary information, the instructions comprising: managing a plurality of target functions, each of the plurality of target functions relating a first type of processing function from a plurality of first type of processing functions to a second type of processing function from a plurality of second type of processing functions; selecting a target function from the plurality of target functions based on a query; and executing the first type of processing function and the second type of processing function on the acquired primary information to generate the secondary information, based on the selected target function.