John, One problem with this type of dataspace is that there isn't a standard method to "own" pieces of dataspace storage. Dataspaces don't have FQE's, DQE's and FBQE's, or the control blocks that manage 64 bit memory objects, so how do you advertise that this piece of the dataspace contains your data? Another problem is that dataspaces are 31 bit addressable, so this would "only" provide 2GiB of relief.
=============================================== Wayne Driscoll OMEGAMON DB2 L3 Support/Development wdrisco(AT)us.ibm.com =============================================== "McKown, John" <[email protected]> Sent by: IBM Mainframe Discussion List <[email protected]> 05/19/2009 01:43 PM Please respond to IBM Mainframe Discussion List <[email protected]> To [email protected] cc Subject common area [E]CSA question / idea / idiocy I'm reading the paper about IBM's plans for the 64-bit common (HVCOMMON?). And I'm really beginning to wonder about something. What this will do is create another block of storage which is mapped into every address space. I am curious why IBM has not considered using AR mode and a SCOPE=GLOBAL dataspace set up and IPL time, anchored to *MASTER* for some of these data areas. At present, from my reading, there are three ALETs with special values. ALET==0 is for the Primary address space. ALET==1 is for the Secondary address space. And ALET==2 is for the Home address space. How about ALET==3 being for a "common GLOBAL data space"? Is there some reason for products such as DB2, IMS, CICS, MQ, ..., requiring that the "common" area be addressable in "primary" mode at all times? Mainly curious. Is AR mode that much more difficult / restrictive than AMODE(64)? John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * (817)-961-6183 cell [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
