PMFJI here, but even if that's true at "a level lower than EXCP", I don't think any of the standard access methods (xSAM, x=B/Q/V) yet supports 64-bit buffers or returned record/buffer addresses, do they? Aren't we mere mortal application programmers still limited to 31-bit buffers?
Peter -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Bill Fairchild Sent: Wednesday, September 12, 2012 5:44 PM To: [email protected] Subject: Re: Data spaces vs hiperspaces Data no longer must be read into buffers in 31-bit storage. You can now do I/O directly into or out of 64-bit virtual addresses with real backing also in 64-bit addressing. I have been doing it for several years with BAM (Bill's Access Method) that uses I/O services at a level lower than EXCP. I'm sure that DB2 and other strategic products of IBM are also doing I/O with 64-bit buffer addresses. Bill Fairchild Programmer Rocket Software 408 Chamberlain Park Lane * Franklin, TN 37069-2526 * USA t: +1.617.614.4503 * e: [email protected] * w: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Gainsford, Allen Sent: Wednesday, September 12, 2012 3:58 PM To: [email protected] Subject: Re: Data spaces vs hiperspaces >That said, there are circumstances where the opposite may be true: that a >hyperspace may provide better performance than 64-bit storage. I had a case >recently, with a program that generates large amounts of data that it needs to >hold temporarily in storage. I tried both ways, and found that a hyperspace >gave better performance. >The reason, I eventually decided, was that the data had to be initially read >from a dataset -- and thus had to be read into 31-bit storage -- and later >written back to a dataset -- again, having to be written from 31-bit storage. >When it came to storing the data away, the overhead of copying it above the >bar, and later copying it back again, was greater than the overhead of leaving >it where it was and using a hyperspace. >If I'd been able to create, and later consume, the data entirely in 64-bit >storage, the reverse would probably have been true. >Allen Gainsford Info Developer, Banking Shared Services HP Enterprise Services (South Pacific) This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.
