RE: SMP experiences

["Elvis Budimlic" <ebudimlic@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Yes.  Let me just qualify your last sentence like "... any CPU work
QUERY OPTIMIZER is involved with ...".
Actually, you should be getting quite a boost from I/O SMP parallel
index maintenance.  You will not get proportionately identical benefit
from CPU SMP but it will definitely help.

Following is a direct quote from the "DB2 Universal Database for iSeries
-
Database Performance and Query Optimization" book.

"Consider SMP and parallel index creation and maintenance:

Symmetrical Multiprocessing (SMP) is a valuable tool for building and
maintaining indexes in parallel. The results of using the optional SMP
feature of OS/400 are faster index build times, and faster I/O
velocities
while maintaining indexes in parallel. Using an SMP degree value of
either *OPTIMIZE or *MAX, additional multiple tasks and additional
system resources are used to build or maintain the indexes. With a
degree value of *MAX, expect linear scalability on index creation. For
example, creating indexes on a 4 processor system can be 4 times as fast
as a 1 processor system."

Elvis

-----Original Message-----
 
So if I understand correctly what I have read and what you are telling
me we
are getting some boost from optimized I/O but could see improved
performance
by adding CPU parallelism because there is also a CPU component to the
index
maintenance.  Additionally any CPU work that could be split into
parallel
tasks would also benefit.