If all the parcels in the response do not fit in one response buffer, the database first sends one buffer-full of the response and later, as directed by CLI, sends the remaining response one buffer-full at a time.
A buffer-full of parcels refers to the number of whole parcels that can fit in the buffer. Parcels do not span buffers. As a rule of thumb, the larger the response buffer, the more efficient the transmission of the response from the database.