On 2020-11-20 12:32, Paul Gilmartin wrote:
jn: https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.4.0/com.ibm.zos.v2r4.hasc300/has2z1_Use_of_unblocked_records_for_SYSIN_and_SYSOUT_data_sets.htmYou should not block SYSIN and SYSOUT data sets because the SAM(sequential access method) compatibility interface will increase overheadby unnecessarily deblocking and blocking data sets.
That seems strange. Who said that? In what context? In the old days, it was important to block SYSOUT. Unblocked input and output contributed to disc threshing, which resulted in reduced performance of the disc system as well as slowing down output speed.
I didn't know that. Should I have RTFM? Is SDB aware of that? If BSAM, is this offset by more calls to WRITE/READ? BLKSIZE is incompatible with DD */DATA, perhaps because the programmer is expected to use F/V rather than FB/VB
---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
