On 7 October 2014 14:06, Robert Haas <robertmhaas@gmail.com> wrote:
>> Is there a way of detecting that we are updating a unique constraint
>> column and then applying the HW locking only in that case? Or can we
>> only apply locking when we have multiple unique constraints on a
>> table?
>> If so, I would withdraw any objection to the HW locking technique.
>
> I'm not up on the details of what Peter's patch does with heavyweight
> locking, but I'd say it this way: if the patch uses heavyweight
> locking routinely, that's probably not going to scale well[1]. If
> the patch detects possible conflicts and uses heavyweight locking only
> in those cases and for the specific purpose of untangling those
> conflicts, then that might well be OK.
Yes, what I meant, just more clearly phrased. Thanks for the link.
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services
