Subject Re: [IBO] Cursor unknown error -504
Author Bob Zirbel
--- In, "Alan McDonald" <alan@m...> wrote:
> > >Another thought...
> > >if IBO is using DB_Key instead of the PK... in whatever
> > >Now whe is the DB_Key invalidated?
> > >Doesn't it lose validity across transaction boundaries?
> >
> > It can/should be expected to. It's "static" in the sense that
it is
> > constructed on the basis of the row's physical location relative
to other
> > rows on a page belonging to that table. It is likely to change
> > if the row
> > gets updated, so it shouldn't be relied on outside the
> > transaction context
> > that it's queried. A new recversion that's been written to a
> > page and/or offset wouldn't be found by the db_key.
> >
> > The exception, though, indicates that the *cursor* is lost. I got
> > thinking
> > about what goes on with this "hands-off" transaction.refresh of
> > yours. Now, if a transaction is set up with Autocommit true,
posting a
> > change or a delete on the current row commitretains the
transaction - the
> > "soft commit" that holds existing cursors open. OK, now, say
the user
> > starts editing something but doesn't post it. She goes off to
lunch and,
> > while she's out, your timer kicks in and forces a
> > transaction.refresh. There won't be anything to commit, because
> > has been posted since the last CommitRetaining. The hard commit
ends the
> > transaction but it also, of course, kills the cursors.
> >
> > The user comes back from lunch and brings up her screen where
she left
> > off. Your transaction.refresh has reopened the dataset, but the
> > edits she left in the control no longer match up with cursor
> > because the hard commits have long since invalidated it. Hence,
when she
> > tries to post, *that* particular edit is going to fail with the
> > unknown error; but any further edits will be OK, because they
will take
> > place in the context of the *new* cursor.
> >
> > If that's the case, it should be easy to catch that exception
> > (its gdscode
> > is 335544572) and just swallow it.
> >
> > Helen
> Not sure this stacks up Helen, I can leave the app sitting there
for an hour
> and it timer refreshes every 5 minutes. Noone touches it, no
errors until
> say the 13th or 20th save, then on this 13th or maybe 20th save,
the cursur
> unknown error pops up. That's on my dev platform with one user
sitting on
> it.
> Alan

I agree with Alan, Helen, my app is only displaying data in the
grid. As far as I know, unless there is a bug, there are no open