Re: Table Definitions DDS or SQL?

[Vernon Hamberg <vhamberg@xxxxxxxxxxx>]

Maybe he was thinking of Joe P - as in Pluta!

At 06:04 PM 10/8/2006, you wrote:

> OK, I'm a bit late reading up on my mail, but next time you define a
> file to allow crap into, would you mind terribly using a different name?
> Otherwise I'll have to think hard what nasty thing to call Rob :-)
>
> Joep Beckeringh
>
>
> rob@xxxxxxxxx wrote:
> > Like Denis, most of our files are defined using DDS.  But that's packaged
> > software for you.
> > I define my new files using SQL.  Then again, I am probably the only one.
> >
> > Here's something to chew over:
> >
> > Problem with DDS created files.  DDS created files are built to allow crap
> >
> > in most fields.  Some legacy thing when people got off grunting, thumping
> > their chest and writing batch programs that checked fields down to the
> > byte level for data that is right.  Like the first COBOL program I wrote
> > in a class - make sure a field that is supposed to be numeric, is.  DDS
> > files are fast to write to, but slow to read from because they don't care
> > what kind of data you write to them.  But they'll check the data quality
> > on a read.  When you think about it, most of your data access is reading,
> > right?
> > SQL created files check data on a write.  Not on a read.
> > Recently saw a classic example of this.
> > Compile this:
> >                 R JOEPR
> >                   MYCHAR         5A
> >                   MYPACK         9P 2
> > with CRTPF FILE(ROB/JOEP) SRCFILE(ROB/QDDSSRC)
> > Run this command:  CRTPF FILE(ROB/JOEP2) RCDLEN(10)
> > STRSQL
> > INSERT INTO ROB/JOEP2 VALUES('NOWISTHETI')
> >
> > CREATE TABLE ROB/JOEP3
> > (MYCHAR CHAR (5 ) NOT NULL WITH DEFAULT,
> >  MYPACK DEC (9 , 2) NOT NULL WITH DEFAULT)
> > RCDFMT JOEP3R
> > (exit sql)
> >
> > CPYF FROMFILE(JOEP2) TOFILE(JOEP) MBROPT(*ADD) FMTOPT(*NOCHK)
> > Notice:  Allowed crap into JOEP.  You have a packed decimal field with
> > alpha characters in it.
> >
> > But CPYF FROMFILE(JOEP2) TOFILE(JOEP3) MBROPT(*ADD) FMTOPT(*NOCHK)
> > Tells me to bugger off with CPF5035-Data mapping error on member JOEP3.
> >
> > Now if I attempt to read the corrupted DDS created file with a simple
> > RPGLE cycle program
> >      FJOEP      IP   E             DISK
> >      FQSYSPRT   O    F   80        PRINTER
> >      OQSYSPRT   D
> >      O                       MYCHAR
> >      O                                              ' '
> >      O                       MYPACK
> > I will get RNQ0907-Decimal-data error occurred.
> >
> > Verifying that DDS files check data integrity on read.  SQL created files
> > check data integrity on write.
> >
> > Rob Berendt
>
> --
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