Re: Making joins involving ctid work for the benefit of UPSERT

On Mon, Jul 28, 2014 at 11:37:07AM -0400, Robert Haas wrote:
> > Yes, but what if you don't see a conflict because it isn't visible to
> > your snapshot, and then you insert, and only then (step 5), presumably
> > with a dirty snapshot, you find a conflict? How does the loop
> > terminate if that brings you back to step 1 with the same MVCC
> > snapshot feeding the update?
> 
> Good point.  Maybe the syntax should be something like:
> 
> UPSERT table (keycol [, keycol] ...) { VALUES (val [, val] ...) [,
> ...] | select_query }

One idea would be to allow UPSERT with constants (single row), and use
CTEs with a SELECT or INSERT/RETURNING for multi-row upserts.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
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