Re: Determining if a record is locked

From: Kevin P. Fleming <kfleming_at_access-laserpress.com>
Date: 1998/03/06
Message-ID: <3500538C.B1139A7C@access-laserpress.com>#1/1

Yes, you can do a SELECT ... FOR UPDATE NOWAIT on the row(s) in question. If the SELECT can't obtain row locks on all of the rows, it will return immediately and there is some way to tell if it worked, although I can't find it at the moment.

Nuno Guerreiro wrote:
>
> On Wed, 04 Mar 1998 15:18:59 -0700, Kent Anderson <anderske_at_agcs.com>
> wrote:
>
> >Is there a way to tell if a record is locked without
> >actually blocking on it?
> >
> >My situation is that we have two processes acting
> >on the same tables in a database. If the first process
> >updates a record, then the second process's update on that
> >record will block until the first process ends its
> >transaction.
> >
> >Is there any way for the second process to determine
> >if the record is locked so it can put it off until
> >later?
> >
> >--
> >+=================================================================+
> >| Kent Anderson Phone: (602) 581-4332 |
> >| Engineer E-mail: anderske_at_agcs.com |
> >| AG Communications Systems |
> >| Phoenix, Arizona "Expand the power of you network" |

 +-----------------------------------------------------------------+


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> >+=================================================================+

>
> I'm sure an exception is raised when the second process tries to
> update the locked record. Try to find out the name of the exception
> and act accordingly to your needs in an exception block or write down
> the ORA error number and test for it.
>
> Nuno Guerreiro
Received on Fri Mar 06 1998 - 00:00:00 CST