Right. That's a better idea. Seek to end minus 'n' and go from there. Only small negative is that if you did the first 'n' bytes and then needed to do the whole file, you could just keep going rather than starting over.
Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Kirk Wolf Sent: Thursday, August 20, 2015 10:31 AM To: [email protected] Subject: Re: Ideas for hash of a sequential data set That is certainly a possibility, but wouldn't help in the (common) case of a change that just appends to the end. Perhaps hashing both the "first n bytes" with the F1/8 DSCB (which has information about the last TTR and bytes in the last track) would cover more of the common changes than either alone. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
