The advantage of using a temporary result writer job in processing
a request is that the temporary result writer can process its request at the
same time (in parallel) that the main job is processing another step of the
query.
Performance advantages of using a temporary result writer are as follows:
- The temporary result writer can use full symmetric multiprocessing (SMP)
parallel support in completing its query step, while the main job can continue
with more complex steps that do not lend themselves as easily to parallel
processing (such as query optimization, index analysis, and so on).
- Because distributed file processing requires communications interaction,
a considerable amount of time typically spent waiting for sending and receiving
can be offloaded to the temporary result writer, which leaves the main job
to do other work.