That is a concept that DB2 uses. It can start at 1 cylinder and increase the secondary by 1 on each extend.
If you changed the SPACE parameter to accept: SPACE=(unit,(n,+m,... Where unit = TRK/CYL/etc and n=Primary allocation and +m is the initial secondary amount and increment That way if you specified SPACE=(CYL,(10,+5)) and got the primary and 10 extents, the file size would be 285 cylinders and a primary with 15 extents would be 610 cylinders as opposed to 60 and 75 cylinders respectively. Amount per allocation - 10 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 Total allocation 10 15 25 40 60 85 115 150 190 235 285 340 400 465 535 610 This might be attractive for an EA enabled data set where even a SPACE=(CYL,(10,+10)) gets you to about 75,030 cylinders in 123 extents. Chris Blaicher Principal Software Engineer, Software Development Syncsort Incorporated 50 Tice Boulevard, Woodcliff Lake, NJ 07677 P: 201-930-8260 | M: 512-627-3803 E: cblaic...@syncsort.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Tom Marchant Sent: Thursday, May 23, 2013 10:33 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: B37 för FTINCL in ISPF for userid.ISPnnnnn.SPFTEMPn.WORK datasets On Thu, 23 May 2013 16:44:55 +0200, Thomas Berg wrote: >The system should allocate/reallocate according to what is needed in >the actual/immediate need for the dataset without dumping the problem >to the user! (Of course limited by appropriate resource constraints.)" For situations like that, I like to use an allocation like CYL,(1,100). Allocate a small primary and a much larger secondary. Maybe also allowing multiple volumes. Perhaps another useful construct would be an allocation where each secondary extent was bigger than the previous. SMS would have a hard time with such a data set though. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ATTENTION: ----- The information contained in this message (including any files transmitted with this message) may contain proprietary, trade secret or other confidential and/or legally privileged information. Any pricing information contained in this message or in any files transmitted with this message is always confidential and cannot be shared with any third parties without prior written approval from Syncsort. This message is intended to be read only by the individual or entity to whom it is addressed or by their designee. If the reader of this message is not the intended recipient, you are on notice that any use, disclosure, copying or distribution of this message, in any form, is strictly prohibited. If you have received this message in error, please immediately notify the sender and/or Syncsort and destroy all copies of this message in your possession, custody or control. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
