> In principle we don't need to sharelock the referencing row in either
> update in this example, since the original row version is still there.
> The problem is to know that, given the limited amount of information
> available when performing the second update.
Ah, ok. I get it now.
Now to figure out how a 2nd or greater update could know whether the row
was newly created or not ...
-- -- Josh Berkus PostgreSQL Experts Inc.
http://www.pgexperts.com