RLSE in SPACE Parameter

balubhat · New User Joined: 04 Oct 2005 Posts: 19 Location: Singapore

Hi

I am facing some problem with SPACE parameter in JCL.
I have job which reads the table and writes into a file. Number of records to be written is quite high almost 1 Million+.
We are using the SPACE parameter for the output file as

// UNIT=SYSDA,
// DISP=(,CATLG,CATLG),
// DCB=(LRECL=400,RECFM=FB),
// SPACE=(CYL,(300,100),RLSE)

And this job takes almost 20 hrs to complete. But when I run the same job without RLSE , the job completes within an hour.
Does RLSE has something to do with the performance of the JCL?

Robert Sample · Posted: Fri Nov 13, 2009 5:55 pm

It is not very likely that RLSE has much to do with the performance of your job. I've never heard of it having an impact, and a job run time going from one hour to almost 20 hours would be an impact. Something else is going on that is causing the run time difference.

dick scherrer · Posted: Fri Nov 13, 2009 9:10 pm

Hello,

One difference in the 2 runs was probably the traffic on the system when they were run.

To read some data from a database and write a million or so sequential records should take a few minutes - not hours (depending on how the query performs). If the query(ies) are poorly written for the database or the database is not properly defined, run times are more sensitive to additional traffic on the database.

None of this is related to RLSE.