On 10 Oct 2012 00:13:30 -0700, in bit.listserv.ibm-main you wrote: >> Q: Why to change the CISZ of the MANx datasets? > >because they are 4096 in size, every since they were created. >I expect better performance if I change it to 26624.
4K is as efficient in using track space as any larger page size CI size for both 3380 and 3390. The most efficient size on 3380 is 22K and 3390 26K. I suspect that having more CI's for a track doesn't cost that much in terms of performance if the total buffer space for a read or write is the same unless the CIs are written when full on an individual basis. An interesting side question is whether the 3380 and 3390 were deliberately designed to be space wasteful for VSAM and other FBA file architectures (HFS, zFS, PDSE, etc.). Clark Morris > > >Walter Marguccio >z/OS Systems Programmer >BELENUS LOB Informatic GmbH >Munich - Germany > >---------------------------------------------------------------------- >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
