Allocation takes time (everything does, of course) but you were allocating either way, right?
OPEN takes time, and you are now doing 'n' OPENs rather than one -- but OPEN is not "slow" -- not as slow as it was once -- and with concatenation you are doing a "mini-OPEN" under the covers every time you move from dataset to dataset. You could try this approach for 10 and try the concatenation approach for the same 10 and benchmark the two. You could also do a combo of the two approaches: instead of concatenating all of them concatenate and process them 10 or 20 at a time. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Joseph Reichman Sent: Tuesday, October 6, 2020 12:35 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: dataset allocation Seemed like I processed 100 files concatenated a lot quicker But I didn’t do any exact testing you may Be right > On Oct 6, 2020, at 3:30 PM, Paul Gilmartin > <0000000433f07816-dmarc-requ...@listserv.ua.edu> wrote: > > On Tue, 6 Oct 2020 14:56:21 -0400, Joseph Reichman wrote: >> >> I posted a problem last week regarding allocating a concatenated dataset a >> few of you (Seymour,Paul Gilmartin) suggested that when processing the 4,608 >> VB (huge) files >> > (I believe Lizette offered a similar suggestion.) > >> That rather then concatenate them and when I reach the limit deco catenate >> them >> >> I just process on file at a time >> Alloc >> Open >> Read >> Close >> Unalloc >> >> Well this process is taking forever. I initially ran the program under TEST >> and it took 3 wall minutes to get to the 58th file >> > How does that compare to the time it takes to process the 58 concatenated? > Doesn't concatenation need the same 58 calls to DYNALLOC to allocate plus > one more to CONCAT? > > But concatenation might spare some OPEN/CLOSE/EOV overhead. > > Does TEST make a difference? > >> I am wondering whether BSAM with above the bar option would be worth the >> effort if it sped things up > > -- gil > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
