> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[EMAIL PROTECTED] On Behalf Of David Logan > Sent: Tuesday, February 05, 2008 10:17 AM > To: [email protected] > Subject: Technical questions about CICS STARTBR and ENDBR > > > I have a product that, due to how the original programmers > have done file > I/O, makes it really difficult for me to easily control it in > CICS. So, with > that, I have some questions: > > I issue a lot of STARTBR commands, usually without any ENDBR > commands. What > are the performance implications? My product has seven files > or so, but can > issue hundreds of STARTBR commands over them. I don't mean performance > implications in terms of time. Does it lock up records? > Consume memory? > Create chains of control blocks? In short, would there be any > reason that > issuing hundreds of STARTBR commands would be bad? > > Similarly, is there any actual reason to concern myself with > ENDBR? All of > these files are read only, so there are no update locking > issues. When the > transaction ends, afaik, all memory, locks, browses, etc. are > released as > well. So what problems might I experience there? > > I'm just not seeing any problem with the methodology being > used to read > data, other than the obvious problem of having to issues > zillions of reads > to the same block (or same set of blocks.) I don't see any > reason it would > consume memory, cause deadlocks, cause CICS to hang or crash, > or anything > like that. > > Am I missing something? Would I need to provide more information? > > Thanks! > > David Logan
Doesn't each STARTBR tie up a VSAM string on the file? It's been a long time, but I remember that we had problems of this sort in the past. I'm not the CICS person anymore. In any case, that is the only thing that I can think of that might be a problem. Well, other than "elegance" in the code. Or, as has happened around ehre, some other code LINKing multiple times to your code and exhausting CICS resources. We had a subroutine that did GETMAINs and no FREEMAINs because it __knew__ that it was only called once per transaction. The somebody called it about 1000 times in one transaction and exhausted DSA (SOS and locked up the CICS region). I am a firm believer in "if I got it, then I should give it back". I do realize that there are times when this may be difficult or maybe even impossible without a lot of rewriting of code. It is just a personal philosophy of programming of mine. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
