Unless something has changed SMB requires the VSAM file to be in extended format, but BLSR does not. From my understanding you can't influence as much around index buffers and data buffers with SMB as you can with BLSR.
We actually use both. Some people like that with SMB you delete/define the file with extended support (SMS management class) and everything is automatic after that. No JCL changes needs unless you want to force SMB to handle things different from the default. >From my point of view both BLSR and SMB have their place. Depending on the >situation BLSR might perform better than SMB or SMB might be better than BLSR. Thanks.. Paul Feller AGT Mainframe Technical Support -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Frank Swarbrick Sent: Friday, July 14, 2017 13:53 To: IBM-MAIN@LISTSERV.UA.EDU Subject: SMB vs BLSR We currently use the BLSR (Batch Local Shared Resources) SUBSYS for some of our brutally randomly accessed files. Something today made me look at the AMP parameter on the DD JCL statement and I saw that it allows you to specify many of the options that BLSR allows, such as RMODE31, BUFND, BUFNI, etc. So now I am wondering what the difference between the two is, and why one might be preferred over the other. Or are they not as similar as I am thinking? Specifically, what would be the difference between this (our current usage): //ICMMSTR DD SUBSYS=(BLSR,'DDNAME=ICMMSTR@ MSG=I', // 'RMODE31=ALL BUFND=10 BUFNI=10') //ICMMSTR@ DD DSN=&DSNENV..ICM.ICMMSTR, // DISP=SHR and this? //ICMMSTR DD DSN=&DSNENV..ICM.ICMMSTR, // DISP=SHR, // AMP=('ACCBIAS=DO,RMODE31=ALL,BUFND=10,BUFNI=10') Any tips? Frank ---------------------------------------------------------------------- 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
