I'd say no, how would you cater for short blocks? -----Oprindelig meddelelse----- Fra: IBM Mainframe Assembler List <[email protected]> På vegne af David S. Sendt: 11. november 2023 14:59 Til: [email protected] Emne: Is True Skip-Sequential Processing Possible with RECFM=FB,DSORG=PS?
To help resolve a question posted to a LinkedIn group I manage: http://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. Note: We already know certain VSAM formats can do this, but the file in question is a DSORG=PS *Sequential* file, *not* VSAM. This is a rock-solid requirement and cannot be changed. We also already know how certain utilities such as SORT and REXX can *mimic* skip-sequential functionality by *discarding* unwanted records until the specified record number is reached. This is a likewise rock-solid requirement. Sequential processing *must* begin at specified starting point and there can be *no* reading of any records prior to that point. My gut feeling is it *cannot* be done - at least not with RECFM=FB. It *might* be possible with RECFM=F, but efficiency would then be so compromised it would probably outweigh any advantage from *true* skip-sequential processing.
