Re: INSERT...ON DUPLICATE KEY LOCK FOR UPDATE

On Fri, Dec 20, 2013 at 3:39 PM, Heikki Linnakangas
<hlinnakangas@vmware.com> wrote:
> Hmm. If I understand the problem correctly, it's that as soon as another
> backend sees the tuple you've inserted and calls XactLockTableWait(), it
> will not stop waiting even if we later decide to kill the already-inserted
> tuple.
>
> One approach to fix that would be to release and immediately re-acquire the
> transaction-lock, when you kill an already-inserted tuple. Then teach the
> callers of XactLockTableWait() to re-check if the tuple is still alive.

That particular mechanism sounds like a recipe for unintended consequences.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company