I possibly could if I had the slightest idea how to do that. Is that something an "applications developer" might have access to, or only a sysprog? Thanks, Frank
----- Original Message ----- > From: Martin Packer <martin_pac...@uk.ibm.com> > To: IBM-MAIN@bama.ua.edu > Cc: > Sent: Wednesday, April 4, 2012 1:34 PM > Subject: Re: VSAM help wanted for random reads > > Not to suggest YOU should've done this but you can get useful statistics > out of SMF 62 and 64 that would've told you how much "write" > activity you > had - and a lot else besides. > > Cheers, Martin > > Martin Packer, > Mainframe Performance Consultant, zChampion > Worldwide Banking Center of Excellence, IBM > > +44-7802-245-584 > > email: martin_pac...@uk.ibm.com > > Twitter / Facebook IDs: MartinPacker > Blog: > https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker > > > > From: > Frank Swarbrick <frank.swarbr...@yahoo.com> > To: > IBM-MAIN@bama.ua.edu, > Date: > 04/04/2012 16:59 > Subject: > Re: VSAM help wanted for random reads > Sent by: > IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> > > > > Tested with DEFERW=YES (that is the proper syntax, by the way. Commas are > optional.) > It didn't gain me much, as I am only updating 32 of 61459 records, so > I'm > not going to worry about it at this time. > > > With BLSR DEFERW=YES: > CSR020I BUFSI=1024, BUFSD=20480, BUFNI=10, BUFND=256, HBUFNI=0, HBUFND=0, > SHRPOOL=14. DDNAME=ICMMSTR > CSR022I STRNO=16, ACB RMODE31=ALL, RMODE31=ALL. > DDNAME=ICMMSTR > +CSR021I ACB CONVERTED TO USE VSAM LSR. > DDNAME=ICMMSTR > - -----TIMINGS > (MINS.)------ -----PAGING COUNTS---- > -STEPNAME PROCSTEP RC EXCP CONN TCB SRB CLOCK > SERV WORKLOAD PAGE SWAP VIO SWAPS > -PROC01 STEP01 00 10649 3485 .04 .00 1.2 > 73938 TSTBAT 0 0 0 0 > IEF404I ICM06F - ENDED - > TIME=09.36.39 > > > > -ICM06F ENDED. NAME-ICM06 TOTAL TCB CPU TIME= .04 > TOTAL ELAPSED TIME= 1.2 > > STATISTICS > > > > REC-TOTAL----------61459 SPLITS-CI--------------0 > EXCPS----------------466 > REC-DELETED------------0 SPLITS-CA--------------0 > EXTENTS----------------1 > REC-INSERTED-----------0 FREESPACE-%CI---------20 > SYSTEM-TIMESTAMP: > REC-UPDATED-----------32 FREESPACE-%CA---------10 > X'C95EC792E74FAC04' > REC-RETRIEVED------10103 > FREESPC---------19886080 > > > With BLSR DEFERW=NO: > CSR020I BUFSI=1024, BUFSD=20480, BUFNI=10, BUFND=256, HBUFNI=0, HBUFND=0, > SHRPOOL=14. DDNAME=ICMMSTR > CSR022I STRNO=16, ACB RMODE31=ALL, RMODE31=ALL. > DDNAME=ICMMSTR > +CSR021I ACB CONVERTED TO USE VSAM LSR. > DDNAME=ICMMSTR > - -----TIMINGS > (MINS.)------ -----PAGING COUNTS---- > -STEPNAME PROCSTEP RC EXCP CONN TCB SRB CLOCK > SERV WORKLOAD PAGE SWAP VIO SWAPS > -PROC01 STEP01 00 10661 4459 .04 .00 1.2 > 74300 TSTBAT 0 0 0 0 > IEF404I ICM06F - ENDED - > TIME=09.53.06 > > > > -ICM06F ENDED. NAME-ICM06 TOTAL TCB CPU TIME= .04 > TOTAL ELAPSED TIME= 1.2 > > STATISTICS > > > > REC-TOTAL----------61459 SPLITS-CI--------------0 > EXCPS----------------471 > REC-DELETED------------0 SPLITS-CA--------------0 > EXTENTS----------------1 > REC-INSERTED-----------0 FREESPACE-%CI---------20 > SYSTEM-TIMESTAMP: > REC-UPDATED-----------32 FREESPACE-%CA---------10 > X'C95ECB3FB8134004' > REC-RETRIEVED------10103 > FREESPC---------19886080 > > > I did a delete/define/repro from source for the ICMMSTR file before each > run. > > > Thanks for everyone's help! > > Frank > > > > ----- Original Message ----- >> From: "Farley, Peter x23353" <peter.far...@broadridge.com> >> To: IBM-MAIN@bama.ua.edu >> Cc: >> Sent: Wednesday, April 4, 2012 7:00 AM >> Subject: Re: VSAM help wanted for random reads >> >> Be very cautious using DEFERW with BLSR unless you already have a good > backup of >> the KSDS immediately before the program starts. Recovery after a crash > (program >> or system) will require a restore of the file, since DEFERW with a crash > can >> leave the KSDS corrupted and sometimes unreadable, in part or in whole. > >> BTDTGTTS. >> >> But it does speed up the update process substantially. If you decide to > use it, >> add the measurements of both the time to take a backup just before > starting the >> program and the program update time to compare to the non-DEFERW time. >> >> If you can allocate sufficient memory for buffers that will hold ALL of > the >> CI's in the file, or at least all of the CI's that need an update > (not >> always practical, of course), all of the updating will occur at CLOSE. >> >> Also note that I added a comma before the DEFERW in Ron's example. >> >> HTH >> >> Peter >> >> -----Original Message----- >> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On > Behalf Of >> Ron Hawkins >> Sent: Wednesday, April 04, 2012 12:35 AM >> To: IBM-MAIN@bama.ua.edu >> Subject: Re: VSAM help wanted for random reads >> >> Frank, >> >> It is terrific that you are getting an improvement with BLSR. >> >> I suspect you are using a vanilla copy of an example in the BLSR manual >> similar to Peter Farley's example in his post. The problem is these > parms do >> not get the best performance from BLSR. >> >> The missing value is DEFERW. This is explained at >> >> > http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA5J600/3.1.1?SH > >> ELF=iea2bkb3 >> < > http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA5J600/3.1.1?S > >> HELF=iea2bkb3&DT=19940301112926&CASE> >> &DT=19940301112926&CASE= >> >> about three quarters of the way down the page. Using Peter's example I > would >> suggest you should use: >> >> //MYKSDS DD SUBSYS=(BLSR,'DDNAME=MYKSDS#','RMODE31=ALL', >> // > 'MSG=I','BUFND=256','BUFNI=10',DEFERW) >> //MYKSDS# DD DSN=HLQ.MY.KSDS,DISP=SHR >> >> If you do omit DEFERW a CI will be written to the KSDS every time you > update it. >> It will stay buffered for a read buffer hit, but if you update 100 > records in >> the CI you will write that CI 100 times. Not a huge problem for most > modern >> DASD, but if you are running synchronous remote copy it will be painful. > With >> DEFERW an updated CI will written when the LSR algorithm decides it is > no longer >> active enough to remain in the LSR pool. You'll also see an unusual > effect >> where all changed CI are written to KSDS at end of job. >> >> DEFERW also helps the performance of sequential inserts that do not use > SIS, and >> CI and CA splits. It's an often omitted must-have for BLSR. >> >> NB it's a good practice to set BUFNI to the number of records in the > Index >> component of the KSDS, plus 10%. Again based on the example, if you have > a three >> level index with 11 index set records your sequence set will pollute the > buffer >> hits on the low level index set records (the high level index set record > is >> probably the most touched CI in the KSDS). >> -- >> >> >> This message and any attachments are intended only for the use of the > addressee >> and may contain information that is privileged and confidential. If the > reader >> of the message is not the intended recipient or an authorized > representative of >> the intended recipient, you are hereby notified that any dissemination > of this >> communication is strictly prohibited. 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