1. A stream data processing method for causing a computer to execute a processing of receiving stream data input to the computer as primary information and of generating secondary information by acquiring primary information within a predetermined period from among the received primary information, comprising the steps of: receiving the stream data input to the computer as the primary information; determining whether or not the received primary information includes delay information indicating that there is primary information to arrive with a delay; and performing a first real-time processing when a result of the determination includes delay information, wherein: the step of performing the first real-time processing includes the steps of: extracting primary information corresponding to a predetermined lifetime from among the received primary information as secondary information, and generating a real-time processing result from the extracted secondary information; receiving primary information corresponding to the delay information; and recalculating the real-time processing result after receiving the primary information that arrives with a delay; the step of generating the real-time processing result from the extracted secondary information includes the steps of: obtaining secondary information based on the lifetime from primary information excluding primary information that is to arrive with a delay when the delay information is received, and outputting the secondary information as a real-time output result that needs to be recalculated; and retaining result restore information for obtaining the real-time output result as information that needs to be recalculated after receiving the primary information corresponding to the delay information, along with the lifetime; and the step of recalculating the real-time processing result after receiving the primary information that arrives with a delay includes the step of recalculating the secondary information from the primary information that arrives with a delay and the result restore information, and outputting a result of the recalculation as a delay output result.