DB2 Symmetric Multiprocessing on AS/400

[sssas400]

Are any XE users using DB2 Symmetric Multiprocessing (SMP) on their AS/400s that have multiple processors?

 

[rjjump]

We haven't done any comparisons for a long time, but I don't think it made much difference to our benchmark tests a long time ago.

Here's the way I look at it:

DB2 SMP allows complex, long running queries to be broken up and pieces are run concurrently on multiple processors.

In general, most OneWorld queries are fairly short, quick running...but there are a lot of them. This type of activity probably wouldn't benefit from DB2 SMP, since they run quickly on one processor.

Depending on what you do in the system, you can use Oneworld in a way that generates longer running, more complex queries. These might benefit from being broken up and running on multiple processors. If users do long running ad hoc queries or other applications do long running, more complex queries, then they might benefit from SMP as well.

So, I think the answer depends on how the system is being used. I don't have any specifics, but have heard of some clients where it made a significant difference and other clients where it had no impact.

 

[sssas400]

Thanks!

 

[Jack_Crouch]

We have it. And we just put in an 840 24 way. I do not know of a way to tell whether it helps or not.

I need to just turn it off, time, then turn it off on various things and try to measure it. I am currently working with IBM Rochester on performance analysis... I will be asking them about this. I will let you know if this is answered in any meaningful way.

AS400 V5R1, XE+XU1+45ESUs, SP16.1, NT-SQL7 for CO