Your application performance will improve using BLSR when direct access is
used and the same CI is referenced more than once in the processing. Using the
BLSR subsystem with sequential access could degrade performance rather than
And there is also in the same manual
4.9.1 COBOL users take note
Note: This information was provided by Helen Witter.
Try to keep in mind is that COBOL is written for NSR processing. If anything is
done to switch the processing to LSR (whether OEM, SMB or BLSR), the
program or COBOL may not be able to handle it.
So if you're not accessing the same RRDS CI multiple times, you're not going to see much benefit to BLSR. And COBOL might prevent you from seeing any benefit, anyway.
The Redbook says BLSR handles RRDS but I'm not sure how much benefit RRDS can get from BLSR -- I've never dealt that much with RRDS to be able to say. Are you doing READ NEXT on the RRDS file or are you using the RELATIVE KEY for random access?