-----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of R.S. Sent: Friday, October 12, 2007 9:00 AM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: ADABAS vs. IMS vs. DB2 Who is faster?
Van Dalsen, Herbie wrote: [...] > The reason why both(DB2/Adabas) are still with us is probably because > they ultimately offer a different set of benefits to their users. Bad assumption IMHO. Mainframe is a dino, a lot of things still exist on mainframe because of conservative users. At a risk of starting new war I can provide some examples: a) VSE. It is obsolete, insecure, in fact "moribound". Oftenly it is run on very small machines, so this workload could be easily run on cheaper platform. The problem is nobody migrated the application. <SNIP> DOCH! I don't think your reasons would be shared by all VSE users. When IBM fixed a few issues creating VSE/ESA, there were shops that migrated BACK to VSE from MVS. That IBM is not "actively" upgrading VSE does not make it obsolete. But those fixes surprised many MVS knowledgeable people who, when migrating a VSE system to MVS, thought that they would immediately gain "performance" because of I/O issues. By giving VSE "XA" I/O (SSCH vs. SIO/SIOF), that old performance boost idea went away. VSE also handles VSAM better than MVS in that sharing of files has better support (well, until "MVS" got record level locking). And then there is the situation where VSE is cheaper to run in terms of software costs. Which is, in my opinion, the reason for the "reverse" migrations from MVS to VSE when VSE/ESA became available (giving XA I/O, increased real storage support, larger Virtual, etc.). Example: a former customer of mine migrated from 2 4381s to 2 P/390s. What they did was very specialized and was handled better using VSE than if they took it off to PCs or *NIX. Also, running on very small machines is an advantage. The equivalent MVS system would take how much more in hardware resources? And the reason for that is all the other stuff that MVS has that those VSE customers don't see a need for. And that aforementioned customer paid for the two P/390s just on the A/C savings alone (in the first 2 months!) by getting rid of the 4381s and ALL their devices! And last I checked, they are still running (10 years later). Then there are a few US State entities that are running VSE. They can't justify the cost to migrate, nor do they want/need to because their "OLD" VSE system does exactly what they need it for. Regards, Steve Thompson -- Opinions expressed are strictly mine -- ---------------------------------------------------------------------- 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
