RE: Question about UDB on iSeries

>Please keep in mind that I know **ZERO** about the iSeries and UDB. 

You know enough to avail yourself of this list, and that more than lots
of people I know that have been in the iSeries (AS/400) community for
years. Don't sell yourself short. Let me start by saying that while I'm
know as the pro-Microsoft bigot on the list, I do actually love the
iSeries.

>iSeries and UDB

First thing I would point out, the iSeries does NOT run UDB! At least
not in the http://http://www-306.ibm.com/software/data/ sense of the
term. The iSeries runs it's own database, that is similar, but not
identical to UDB. As time moves forward there is more of the common UDB
code base on the iSeries, but don't expect to pickup a UDB database on
one machine and drop it on another. 

>everything that we need, with a few exceptions, is integrated 
>into the i5OS on the iSeries. 

Yup! And that's the beauty of OS/400 -- and it's curse. Want to do
backup? It's in there! Want security, it's in there! Want TPM? It's in
there. Want a web server? It's in there. Don't like IBM's backup, too
bad! Want a different security engine, oh well. Prefer to use Tuxedo as
the TPM, nope! Don't get me wrong, the tools IBM provides are excellent!
And the power of the OS is that the tools are all integrated. I'm just
saying that one of the differences is that you don't have the selection
you have on z/OS.

>...why UDB on iSeries does not require any such software ...
>...DB2 on z/OS really requires a lot of extra cost software.

Depends on how you look at it. It's not that there isn't a need for
compressing out deleted records, nor is it that there isn't a need for a
performance monitor. The issue is that those needs are fulfilled by the
OS itself, so why would you look for another solution? As for "extra
cost", I'd say that too is a matter of how you look at it. You're paying
for all those tools, you're just paying for them in the cost of the OS. 

Finally, I would point out that the lack of a tool to do something on
the iSeries doesn't mean that the machine wouldn't benefit if the tool
was there. Take reorganizing an index. I cannot (unless someone can show
me a way) reorganize in index. That is to say that I cannot force the OS
to restructure the pages that make up the index tree in a sequential
pattern on the underlying drives. 

Now many will say that that is a benefit of the OS -- and to some degree
they are correct. In many cases the IO subsystem on the iSeries is
powerful enough that I don't need to worry about index fragmentation.
And in most cases, especially highly interactive random IO, a sequential
index might not help at all. However, if you came across a case where it
would -- say an index that could act as a covering index for a sql
statement that needed to read thousands of rows, thousands of times, you
do not have the ability to reorganize an index.

Let me reiterate; I'm not saying that the lack of these tools makes the
iSeries a bad machine, in fact, as I said, I think it's a great machine.
I'm just saying that there are cases where these tools have benefit, and
we cannot avail ourselves of these tools in those cases since they don't
exist.

-Walden

------------
Walden H Leverich III
President & CEO
Tech Software
(516) 627-3800 x11
WaldenL@xxxxxxxxxxxxxxx
http://www.TechSoftInc.com 

Quiquid latine dictum sit altum viditur.
(Whatever is said in Latin seems profound.)
 
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of McKown, John
Sent: Tuesday, 30 November, 2004 09:06
To: midrange-l@xxxxxxxxxxxx
Subject: Question about UDB on iSeries

Please keep in mind that I know **ZERO** about the iSeries and UDB. We
are considering a conversion from z/OS on zSeries to i5OS on iSeries.
The company doing the presentation basically said that everything that
we need, with a few exceptions, is integrated into the i5OS on the
iSeries. In particular UBD is integrated (so we don't need to buy it).
But I was wondering if any iSeries people out there have an opinion
about the lack of requirement for any extra software to support UDB on
iSeries. Such as performance monitors, reorganization utilities,
anything at all? I'm confused (as usual) about why UDB on iSeries does
not require any such software while it appears, to me, that DB2 on z/OS
really requires a lot of extra cost software. This is the whole reason
that we are considering this conversion. z/OS simply requires too much
extra cost software compared to other platforms.

> --
> John McKown
> Senior Systems Programmer
> UICI Insurance Center
> Information Technology
> 
> This message (including any attachments) contains confidential
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> 
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