Re: A question about record locks

[Pete Helgren <Pete@xxxxxxxxxx>]

Chris, Simon, Wilt,

If program 1 issues a CHAIN(N) on the record then it cannot issue an 
update immediately after?  I understand that using a chain(N) and then 
an update is dangerous, someone else could have updated the record, but 
are you saying a chain(n) and then update would fail because it cannot 
be done?  I'll have to go back at look at the code, seems to me it does 
do a chain(n) and then an update but as Wilt said, maybe I missed 
another chain somewhere.

How about SQL ?  If embedded SQL was used to read through the records in 
the posting program B, when someone was maintaining a record in program 
A, would the SQL fetch fail for the same reason?

Thanks for the information.  I'll have to review the code and ponder 
this a bit more.

Pete


Chris Bipes wrote:
> You can have both applications updating the file, but only one program
> can update a record at a time.  You can try changing the lock wait time
> on the posting program to *nomax or something shorter than forever but
> long enough for the user to complete their update.
>
> The other way is to read the record in the maintenance program with no
> lock, save the original image in a data structure, have the user make
> their changes, then after all edits are passed, read the record with a
> lock and see if anything has changed from the original saved image and
> if not changes, update the file.  This way the lock is only for a second
> under program control and not locked while the user is making changes or
> home for the evening.
>
> I have a sample somewhere that I can share showing how to code a simple
> file update.
>
>
> Christopher Bipes
> Information Services Director
> CrossCheck, Inc.
>
>