Well, I'll take a shot at this, even though my
exposure to this platform is limited,,,

DB2/400 (or DB2 UDB for iSeries now) has a different
design philosophy than either UDB/Unix & Windows or
DB2 OS/390. They are 3 different code bases.

Basically it is the *native file system* of OS/400 -
a fully integrated part of the operating system.
(kinda like OSAM on the OS/390 platform). DB2/400
manages all access to files, whether sequantially or
via SQL.

So, all AS400s should have DB2/400. Current release
is 5.2 I think.

The SQL is essentially the same (a few functions are
not supported, but the vast majority of SQL is).
Internal file structure is (as you say) totally
different, as is the Optimizer.
Just like in Unix/Windows vs OS/390 - some things
are better, some things are worse.
Better: bitmap indexes, auto-generation of indexes
Worse: support for Stored Procedures, UDFs, UDTs.
Harder to find experienced resources.

So, from a user (SQL) perspective, its just like the
others. From a DBA perspective its totally
different...

Hope this helps.
Jeremy Bell
Not a AS/400 person, but Certified DBA on Windows/Unix
and OS/390...

> --- Stephane Paquette
> <stephane.[Email Address Removed] wrote:
> Hi,
> We are evaluating a product that would be hosted
> at a the third party. The
> product runs on db2/400
> Can someone tell me if db2/400 is like db2 udb or
> not.
> It seems to me to be at set of files without
> relationnal integrity.
>
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