On Fri, Jan 10, 2014 at 10:01 PM, Greg Stark <st...@mit.edu> wrote: >> So you schedule a class that clashes with 3 other classes, and you >> want to update all 3 rows/classes with details from your one row >> proposed for insertion? > > > Well, perhaps you want to mark the events as conflicting with your new event?
But short of a sophisticated persistent value locking implementation (which I'm pretty skeptical of the feasibility of), more conflicting events could be added at any moment. I doubt that you're appreciably any better off than if you were to simply check with a select query, even though that approach is obviously broken. In general, making row locking work for exclusion constraints, so you can treat them in a way that allows you to merge on arbitrary operators seems to me like a tar pit. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
