On 25 October 2014 19:00, Noah Misch <noah@leadboat.com> wrote:
>> So I tentatively propose (and with due regard for the possibility
>> others may see dangers that I've missed) that a reasonable goal would
>> be to lower the lock strength required for both CREATE TRIGGER and ADD
>> FOREIGN KEY from AccessExclusiveLock to ShareRowExclusiveLock,
>> allowing concurrent SELECT and SELECT FOR SHARE against the tables,
>> but not any actual write operations.
>
> +1
All of this is just a replay of the earlier conversations about
reducing lock levels.
My original patch did reduce lock levels for CREATE TRIGGER, but we
stepped back from doing that in 9.4 until we had feedback as to
whether the whole idea of reducing lock levels was safe, which Robert,
Tom and others were slightly uncertain about.
Is there anything different here from work in my original patch series?
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services