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

On 1/10/14, 4:40 PM, Peter Geoghegan wrote:
> My problem is that in general I'm not sold on the actual utility of
> making this kind of row locking work with exclusion constraints. I'm
> sincerely having a hard time thinking of a practical use-case
> (although, as I've said, I want to make it work with IGNORE). Even if
> you work all this row locking stuff out, and the spill-to-disk aspect
> out, the interface is still wrong, because you need to figure out a
> way to project more than one reject per slot. Maybe I lack imagination
> around how to make that work, but there are a lot of "ifs" and "buts"
> either way.

Well, the usual example for exclusion constraints is resource scheduling (ie: scheduling what room a class will be held
in).In that context is it hard to believe that you might want to MERGE a set of new classroom assignments in?
 
-- 
Jim C. Nasby, Data Architect                       jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net