Re: Normalization was Left AS/400 and Returned -- MIDRANGE-L

Well...no...what I'm saying is that are many iSeries programmers who won't
use join logicals or SQL because it's not a technique that existed 30 years
ago. That doesn't mean that native I/O techniques are bad, simply that there
are other methods, and being tied to a single method of processing (because
that's all they ever wanted to learn) is less than optimal. I remember when
structures (well, semi-structured) opcodes came out in RPG/II on a S/36. I
couldn't imagine anyone not using something that made code easier to write
and understand. And I'm going to be at a client soon that still doesn't use
them...on an 825...running V5R3.

On 5/3/05 03:28 PM, "MWalter@xxxxxxxxxxxxxxx" <MWalter@xxxxxxxxxxxxxxx>
wrote:

> So, what you're saying Michael is that native I/O is a 30 year old
> technique, and is akin to RPG II? Whereas, if you want to be 'modern' you
> must use SQL or Join Logicals? Hmm. Let me think about that for a while.
> 
> Thanks,
> 
> Mark
> 
> Mark D. Walter
> Senior Programmer/Analyst
> CCX, Inc.
> mwalter@xxxxxxxxxx
> http://www.ccxinc.com
> 
> 
>                  
>            michael@ryantechn
>            ology.com
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>                                      RE: Normalization was Left AS/400
>                                      and Returned
>            Please respond to
>            Midrange Systems
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> 
> 
> Of course, a lot of RPG programmers don't use join logicals. Instead,
> they provide their own indexed file navigation by getting a value from
> one file, using that value to chain to another file, getting value from
> that file, chaining to another file...and on and on. There's a divide in
> AS/400-land...those that can/will use SQL or join logicals and want a
> normalized database, and those who have a series of indexed files and
> do their own navigation. Basically, if a programmer wants to use more
> modern techniques, the iSeries can support them. And of course, if a
> programmer still wants to code in RPG/II, they can. The ability to use
> 30 year old techniques is a 'feature' on the iSeries.
> 
> 
>> -------- Original Message --------
>> Subject: Re:  Normalization was Left AS/400 and Returned
>> From: rob@xxxxxxxxx
>> Date: Tue, May 03, 2005 2:55 pm
>> To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
>> 
>> I agree on the multi-format and join logical files.  Or, SQL's views.
> And
>> highly recommend them for programming, and, most especially, for common
>> links the users use in Queries instead of having them join multiple files
> 
>> together.
>> 
>> However, he might be right about the performance issue.  For example,
>> which would access faster:
>> 1 - A key over customer number and part number in a de-normalized
>> order/line file.
>> 2 - A join logical that joins the order/header file with the order/line
>> file so that you can see the customer number from the order header file
> at
>> the same time you see the part number of the order line file.  And, keep
>> in mind, that a join logical file does not allow keys from more than one
>> file, even though I suspect every new release of OS/400 has formed yet
>> another DCR requesting this feature.  This might be possible with an
> index
>> on a view in SQL but I don't think that's allowed either.  I know you can
> 
>> get the data this way in a normalized database via SQL but it's going to
>> do some work under the covers and performance may suffer.
>> 
>> Rob Berendt
>> --
>> Group Dekko Services, LLC
>> Dept 01.073
>> PO Box 2000
>> Dock 108
>> 6928N 400E
>> Kendallville, IN 46755
>> http://www.dekko.com
>> 
>> 
>> 
>> 
>> 
>> "Bill Meecham" <bmeecham@xxxxxxxxxxxxxxxxxxxx>
>> Sent by: midrange-l-bounces@xxxxxxxxxxxx
>> 05/03/2005 01:33 PM
>> Please respond to
>> Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
>> 
>> 
>> To
>> "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx>
>> cc
>> 
>> Subject
>> Re: Left AS/400 and Returned
>> 
>> 
>> 
>> 
>> 
>> 
>> That's not necessarily true since multi-format and join logical files can
> 
>> be created and created much easier when the database is normalized.  The
>> reason shops don't normalize is more likely because it's difficult to
>> master and there is little perceived benefit.  Borrowing from another
>> thread, that's a large part of what case tools help with....normalization
> 
>> and 'virtualization' of fields.
>>   ----- Original Message -----
>>   From: michael@xxxxxxxxxxxxxxxxxx
>>   To: Midrange Systems Technical Discussion
>>   Sent: Tuesday, May 03, 2005 2:25 PM
>>   Subject: RE: Left AS/400 and Returned
>> 
>> 
>>   The reason that most vendors and shops don't have normalized databases
>>   is because most vendors and shops don't use the data store on the
>>   iSeries as a database - it's used as a system of indexed files.
>>   Normalization in that scenario can hurt performance, because the
>>   program would need to chain to several files to gather the information
>>   needed to present to the user. There's no doubt that normalization is a
>>   good thing for a database (at least 3NF), but normalization for indexed
>>   files isn't as important or desired.
>> 
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