To provide optimal performance, the Stream operator packs individual DML statements into a larger multistatement request based on the rate specified by the Pack attribute. This type of processing requires less overhead than multiple individual requests.
The Stream operator submits these multistatement requests using macros which it creates to hold the requests. The macros are then executed instead of running each individual DML statement.
The macros are automatically removed after the job is complete. The use of macros in place of lengthy requests helps to minimize both network and parsing overhead.