CPU Time Batch Job accessing DB2 - Z/OS

[mikerexx]

I am tuning a DB2 batch program. I dont have access to a good monitor. So I will compare CPU times. My question is:

When a batch job finishes, it shows excp, cpu time, etc.

What does the CPU time represent? Does it represnet the time only for the app's TCB or does it include the time spent in the DB2 subsystem's TCB also?

 

[fredericofonseca]

includes all.


see if you have Insight for DB2 or any other tool, as that will enable you to see exactly what time is being spent in what with relation to DB2

Regards

Frederico Fonseca
SysSoft Integrated Ltd

http://www.syssoft-int.com

FAQ219-2884
FAQ181-2886

 

[MarcLodge]

Mike,
I believe that the CPU time shown for the step/job is the total CPU for that step/job. If CPU is used outside of DB2, then this is included in that total.

One thought which occured to me which was whether you are able to add EXPLAIN to the bind statements. This will not only give you a PLAN_TABLE to look at, but if you have a DSN_STATEMNT_TABLE also allocated, you can look at the estmiated costs of each specific SQL statement within the program.

Hope this helps,

Marc

 

[mikerexx]

Thanks,

Fred, my thoughts were that it does include both/all. I have a call into the db2 sysprog as to the monitors that are available.

Marc,
I have run explain extensively and created an index to help with access paths. This does the trick. Now I am trying to put together objective run time stats to back up my recomendations. Hence, the cpu time query.

BTW,
The EXCP count must be channel io for the app only - not all the io for the DB2 subsystem. Agreed?