From: Bruno Wolff III <bruno@wolff.to>
To: Jeffrey Pogodzinski <jrpogo@yahoo.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: libpq program SELECT FOR UPDATE and TIMEOUT or CANCEL REQUEST
Date: Fri, 23 May 2003 10:08:16 -0500
Message-ID: <20030523150816.GA3935@wolff.to> (raw)
In-Reply-To: <11c19c42.0305190955.967d34@posting.google.com>
References: <11c19c42.0305190955.967d34@posting.google.com>
On Mon, May 19, 2003 at 10:55:23 -0700,
Jeffrey Pogodzinski <jrpogo@yahoo.com> wrote:
> Hi,
>
> I am programming using libpq under Linux.
>
> When I do a "select ... for update" to lock a row, how
> would I allow user to cancel or timeout when requesting the
> the same row from another program/transaction.
You can set statement_timeout.
> I do not want the user to have to wait for the update on the
> other end. I would rather send the user an error message
> saying that the record is LOCKED -- try again later.
It is generally bad design to hold database locks while waiting for
user input. It is generally better to keep information about updates
in a table and have the applications use this information to advise
or prevent conncurrent updates to the same data by different people.
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To: pgsql-sql@postgresql.org
Cc: bruno@wolff.to, jrpogo@yahoo.com
Subject: Re: libpq program SELECT FOR UPDATE and TIMEOUT or CANCEL REQUEST
In-Reply-To: <20030523150816.GA3935@wolff.to>
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