Re: Using joinfiles w/ large databases, referential integrity

From: Charles Wilt <cwilt_at_nospam.miamiluken.com>
Date: Mon, 23 Sep 2002 13:20:04 GMT
Message-ID: <MPG.17f8decf2e6521709897d7_at_news.easynews.com>


Pablo mentions it but it bears repeating, whoever gave you your information is working from a combination of very, very old info and just plain wrong information.

Any modern AS/400 (new models are known as the eSearver iSeries) is more than capable of handling TB DBs with all the features you'd expect. In fact, given the hardware-software integration of the iSeries, you may find it better than Oracle or any MS-stuff you may be used to.

Try looking around here:
http://www-919.ibm.com/servers/eserver/iseries/developer/bi/teraplex/

I would venture a guess that the customer you are working with has an application that dates back quite a long time. Not an unusual occurrence in the AS/400 world. Applications with roots back in the System/36 or System/38 can be difficult to retrofit with all the bells and whisles now common in the RDBMS world. Particularly hard to justify given the application has been running 10-20 years without such features.

Charles

In article <3d8c43cc.5995380_at_news.ch.kpnqwest.net>, rhairgroveNoSpam_at_Pleasebigfoot.com says...
> Hi,
>
> I do a lot of database development, but haven't worked with DB2 on
> AS/400 too much since most of my previous work has been in Oracle and
> MS-related stuff on Windows.
>
> We are doing some work now for a company which gets their data from a
> different company which has a large database on DB2 running on AS/400
> or some other IBM mainframe (I don't know how large, but it is large
> .. presumably something in the terabyte range).
>
> Everything is in flat files, no FK constraints, PK constraints are
> only on paper, nothing is journalled, etc. All referential integrity
> and business rules are apparently implemented by server procedures,
> and the data is only in 1st normal form (at best).
>
> Since we only read their data, it doesn't really matter to us as long
> as they keep it consistent. Just out of curiosity, though, I asked one
> of their developers why there are no constraints in the database and
> the response was that it is apparently quite painful to rebuild the
> joinfiles (i.e. constraints) with a large database on AS/400 if they
> ever "break" (whatever that means, "painful" meaning a downtime of
> several days).
>
> So my question to you is: How many people work with such large
> databases and still use constraints with referential integrity
> enforced through joinfiles? Is there another possibility? Or is it
> just too impractical above a certain size? What limits are considered
> too large for DB engine-level RI in the AS/400 and mainframe world?
>
> As I had always been taught to normalize and use sufficient
> constraints with RI, I must admit that I had trouble getting used to
> the idea that many serious applications don't use them at all.
>
>
> Bob Hairgrove
> rhairgroveNoSpam_at_Pleasebigfoot.com
>
Received on Mon Sep 23 2002 - 15:20:04 CEST

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