Program executes very very slowly in production

Keanehelp · New User Joined: 27 May 2008 Posts: 71 Location: USA, CA.

Hi,

We implemented a COBOL DB2 program in production and notice that it takes very long time to execute, however same program executes (with same amount of data) within minutes in Test region.

Please note that we have executed RUNSTATS and REORG utilities on all the DB2 tables in the program.

Please suggest what could be the possible reasons for this.

Thanks & regards

dbzTHEdinosauer · Posted: Thu Oct 08, 2009 6:16 pm

duh, like what else is running in production (at the same time) as this new job.
in other words, what else is going on in the box?

same kind of problem when one tests a car on a race track and it goes 200 mph.

but, (gee, i have no idea why) one can not travel at 200 mph on normal highways.

Keanehelp · New User Joined: 27 May 2008 Posts: 71 Location: USA, CA.

Thanks for the reply,

Actually I thought of such scenarios and executed the program at different times in the production and got the same result.

I am wondering what could be the other possible reasons apart from the heavy traffic?

Thanks

Nitin

GuyC · Posted: Thu Oct 08, 2009 6:26 pm

Comparing explains might show a difference.
but probably dbz is right
-cpu contention
-locking
-bufferpools
-kind of disks
-wlm environments
...

All kind of differences besides "same amount of data" can cause this.

Terry Heinze · Posted: Thu Oct 08, 2009 7:44 pm

If you have a monitoring tool such as STROBE, that can help find the reason(s).

Keanehelp · New User Joined: 27 May 2008 Posts: 71 Location: USA, CA.

No, we do not have STROBE in our shop, also I executed each query using QMF in production and all of them appears to be executing pretty fast.

Also it can not be CPU contention as my program got around 720 CPU minutes after which it was cancelled.

Any thoughts??????

GuyC · Posted: Thu Oct 08, 2009 8:25 pm

720 CPU minutes ???

Did you compare output of explain?

Running a query in QMF is no measurement for accesspath selection.
because in your program you probably have hostvariables and in qmf you have literals.

Keanehelp · New User Joined: 27 May 2008 Posts: 71 Location: USA, CA.

Thanks for the tip, I'll compare the EXPLAIN