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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 > Sent by: To > midrange-l-bounce Midrange Systems Technical > s@xxxxxxxxxxxx Discussion > <midrange-l@xxxxxxxxxxxx> > cc > 05/03/2005 03:08 > PM Subject > RE: Normalization was Left AS/400 > and Returned > Please respond to > Midrange Systems > Technical > Discussion > <midrange-l@midra > nge.com> > > > > > > > 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. >> >> -- >> This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing >> list >> To post a message email: MIDRANGE-L@xxxxxxxxxxxx >> To subscribe, unsubscribe, or change list options, >> visit: http://lists.midrange.com/mailman/listinfo/midrange-l >> or email: MIDRANGE-L-request@xxxxxxxxxxxx >> Before posting, please take a moment to review the archives >> at http://archive.midrange.com/midrange-l. >> >> >> -- >> This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing > list >> To post a message email: MIDRANGE-L@xxxxxxxxxxxx >> To subscribe, unsubscribe, or change list options, >> visit: http://lists.midrange.com/mailman/listinfo/midrange-l >> or email: MIDRANGE-L-request@xxxxxxxxxxxx >> Before posting, please take a moment to review the archives >> at http://archive.midrange.com/midrange-l. > > -- > This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list > To post a message email: MIDRANGE-L@xxxxxxxxxxxx > To subscribe, unsubscribe, or change list options, > visit: http://lists.midrange.com/mailman/listinfo/midrange-l > or email: MIDRANGE-L-request@xxxxxxxxxxxx > Before posting, please take a moment to review the archives > at http://archive.midrange.com/midrange-l. > >
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