Re: Why SAP, PeopleSoft, Siebels Move from Oracle to DB2 ?

hehehe! nothing like a counter-claim to put the cat amongst the pigeons at IBM-city, eh? :-D

Serge Rielau doodled thusly:

>DB2 is the same on all Unixes, Windows and OS/2.

no. it's called UDB. IBM "renamed" it as "DB2 UDB". to make it sound like UDB is DB2.

>It is 100% different server side code on
>OS/390 and AS/400.

no. the code in OS390 is 100% different from the other two. the code in AS400 is 100% different from the other two. Ie, in total 200% different! :-)

>I am not aware of an IBM site claiming differenly (only of competitors
>claiming that IBM claims).
>

heh! Haven't been to the db2 website, have you? :-D darn thing is advertised as the same product all over the place, when it isn't.

anyone with even limited historical knowledge of AS400 and mainframes knows that only too well. it's only the "newbies" that believe this IBM marketing.

>To put things into relation:
>Oracle doesn't run on AS/400 (naturally since the OS/400 and DB2 are pretty much the
>same).

thank God it doesn't! and OS400 and DB2 are NOT the same thing. OS400 had a relational SQL-based database inbuilt since it's very beginning (in the early 80s), and IBM themselves NEVER claimed it was DB2.

It's only since the latest "DB2 everywhere" bull started two years ago that IBM now claims it is "DB2". never was, never will be.

>Oracle practically has no presence on the 390.

Again, thank God. most probably because the 390 practically has no presence!
the darn things are complete dinossaurs, re-invented as "e-servers" by some deranged marketeer inside IBM...

and yet, despite all that, Oracle still runs EXACTLY the same way in all platforms. and with the same code. different link libraries, though.

>The code has to be different to succeed on a mainframe. Its a different platform from
>UNIX, intel servers,
>or rather vice-versa, to get the timeline right.

precisely. DB2 started (in 1979) and has always been a mainframe MVS (later re-badged as OS390) product.

ALWAYS. right down to the 16Mb "line" addressing limitations of MVS and OS390.

even as late as last year it STILL suffered from those limitations.

UDB was and always will be a UNIX/NT product. designed, coded and tuned for that platform. and IBM can claim it is the same as DB2 until the cows come home, it will never be the same. it has many fundamental differences.

to start with: DB2 in the mainframe is a shared-all architecture, while UDB in Unix is a shared-nothing architecture.

something that right upfront makes the two products completely different in terms of database and application design.

as IBM themselves like to point out when referring to Oracle and its shared-all architecture, versus UDB's shared-nothing.

funny how shared-all suddenly becomes "desirable" once it's part of DB2 in the mainframe, eh? LOL!

>
>I agree with Mark that this thread probably has exceeded its life expectancy.
>And I will yield by not posting further comments regarding this thread.
>

thanks. didn't expect otherwise. it's been a constant since this whole debate about "same product" started: as soon as all those wild claims are challenged on the technical level, the conversation ceases.

Roger Miller (DB2 chief architect), Richard Yevich and Susan Lawson in their DB2 tuning book OPENLY ADMIT the mainframe product is COMPLETELY different in performance behaviour from the product in the other two platforms.

furthermore, they ALSO openly admit that anyone designing a high performance application for "DB2" in one platform WILL have problems moving it to another of different codebase. ie, from AS400 to UDB and/or DB2, or from UDB to DB2. let's not even consider the other way around...

which goes against IBM's wild claims about "unlimited scalability" by "moving apps to the big iron". and other loads of crap it's been getting away with.

First time anyone tries to scale that way, all heck is gonna break loose. then we'll see how "compatible" the three really are...

Cheers
Nuno Souto
nsouto_at_optushome.com.au.nospam Received on Fri Jan 11 2002 - 07:56:44 CST