Joined: 26 Apr 2004 Posts: 4650 Location: Raleigh, NC, USA
Searching the Internet, I found this reference to a DD statement (not a parameter) named VIOCTL that is used for a product called VIOPLUS:
Check with the Software Group on the use of VIOPLUS, Coding a special DD statement can improve a batch jobs CPU and run time performance. You can reduce the number of EXCP to a VSAM dataset by up to 50% with correct choices, along with reducing run time or response time by 70%. In fact the best performance can be gained by adding the follow statement to any JCL step that uses VSAM.