Subject RE: [IBO] Cursor unknown error -504
Author Alan McDonald
> >Another thought...
> >if IBO is using DB_Key instead of the PK... in whatever circumstances..
> >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 different
> 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 nothing
> 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 unposted
> edits she left in the control no longer match up with cursor handle,
> because the hard commits have long since invalidated it. Hence, when she
> tries to post, *that* particular edit is going to fail with the Cursor
> 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