Re: Preventing Record lock for Subfile being loaded

Hi Bill,

     In my opinion, this is the best way to handle things.  Load the
records into a subfile without locking them, and then re-load each
record (and lock it) when its time to do the update.

When the READ statement reads a record, it locks it.  Then, when the
program does the next READ statement (for the same file) it releases
that lock, and locks the new record it reads.

This means that if your subfile program does not use the 'N' operation
extender, it will always lock the last record that you loaded... which
usually doesn't do anyone any good -- and will cause problems when
two or more people try to run your program at a time.

Make sense?

You should do the exact same thing in RPG IV that you'd do in RPG III,
nothing has changed, except (slightly) the layout of your C-spec.
In RPG IV, you put the operation extender in parenthesis after the
operation code...  (thats true of half adjusts, padding, and other
things as well as the N=no lock)

     C                     READ MYFILE              N    99
     C                     MOVE ONEFLD    TWOFLD    P
     C                     ADD  5.345     MYNUM     H

becomes:
     C                   read(N)   MyFile
     C                   move(p)   OneFld        TwoFld
     C                   add(h)    5.345         MyNum

Good Luck!


Bill Graziano <Bill.Graziano@besi.com> wrote:
>
> I was looking at an RPG/400 example for a subfile program which
>  UPDATES a file.  In the example, an "N" was palced in the H/P/N
>  column to indicate that the Read statement not lock the record
>  while the subfile was being loaded for display.  I realize that
>  there is no reason to lock the file until the update is going
>  to be performed. However, I have also looked at RPGIV examples
>  in which this was not indicated.
>
> Is this common practice while loading subfiles before the update is
> executed?
>
> What is the RPGIV equivalent of this example?
>
> Thanks,
> Bill Graziano
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