Re: EOFW not resume

On Sun, 2004-11-28 at 20:42, Michael wrote:
> Question:
> =========
> The RPG program resume from EOFW when I insert a new record into the
> physical file which status='OS'.  But the problem is that, the
> program does not resume when I change the status of an existing
> record from other values to 'OS'.
> 
> In the view of the logical file, there is a new record if a message's
> status is changed from other values to 'OS' in the physical file.
> 
> Any mistake in my method?  Any method to fix it?  Thank you!

EOFW means "End of File Wait".  Simply put, adding a record to the file
causes the program to wake up and respond to the new record.  It doesn't
catch updates.  It's a very old method from at least the System/38 days.

If you want to catch updates, you have a couple of options:

1)  Change the program so that it does a SETLL on the logical, reads all
the records, then sleeps via DLYJOB for a predetermined amount of time
(say, a minute).  Then repeat.  The downside is that it can take up to a
minute to respond to a new or changed record which may or may not be
acceptable in your application.  

2) Use a database trigger.  Add a trigger to your transaction file, and
then write a trigger processor to take care of any changes.  It's a bit
more convoluted, but it will be more responsive than option 1.

You could also use journals, or data areas as message passing
mechanisms, but I would probably go with option two.
--
Regards,
Rich

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