On Sat, 11 Nov 2023 08:59:07 -0500, David S. <dlstaudac...@gmail.com> wrote:
>To help resolve a question posted to a LinkedIn group I manage: >www.linkedin.com/feed/update/urn:li:groupPost:910927-7128598004344786944 >... I'd like to find out if there's any way to achieve *true* >Skip-Sequential processing with a Fixed Block Sequential File with a fairly >short record length (i.e. DCB=(DSORG=PS,RECFM=FB,LRECL=80)? >For example: Begin sequential processing at record number 100, *without* >having to read the first 99 records. As another user mentioned, you can't really read portions of blocks, so whatever block contains record number 100 would need to be read, which might give you some extraneous data transfer. The real issue is your RECFM=FB. With FBS it would be possible, as with FBS you know that all blocks up to the final one are the same size, and that would allow you to calculate the block you needed. But with FB you could have short blocks in the middle, making it impossible to calculate where record 100 is located. Another issue, I suppose, is what language you're writing in, as I believe only some access methods would allow you to position the file based on a block number. -- Walt ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
