Great detective work. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Tom Marchant Sent: Friday, January 19, 2018 7:11 AM To: [email protected] Subject: Re: [IBM-MAIN] VSAM Performance - CPU reduction
On Fri, 19 Jan 2018 14:37:31 +0100, R.S. wrote: >IMHO the CISZ was up to 32kB for a veeery long time (since VSAM >beginning perhaps). >The most important is one could use any CISZ on any disk geometry, >including 3380 or 3350, or older. >Of course PB (Physical Block) could be different, as well as number or >PB per CI. The OS/MVS Overview manual, GC28-0984-0, dated June, 1978, is available on bitsavers at http://bitsavers.trailing-edge.com/pdf/ibm/370/OS_VS2/Release_3.7_1977/GC28-0984-0_OS_VS2_MVS_Overview_Rel_3.7_Jun78.pdf On pages 8-18 and 8-19 (151-152) talks about control intervals and has this: <quote> The size of the control interval need not correspond to the size of a track on the device. Figure 8.9 shows the independence of control intervals from physical records, which are limited by the capacity of a track on a particular device. </quote> This confirms Ron's and Radoslaw's memory. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
