On Mon, Sep 29, 2014 at 3:02 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> That'll make it really hard to actually implement real MERGE.
>
> Because suddenly there's no way for the user to know whether he's
> written a ON condition that can implement UPSERT like properties
> (i.e. the *precise* column list of an index) or not.
Exactly. The difficulty isn't doing what Kevin says so much as doing
so and then at a later date taking that thing and making it into a
fully featured MERGE. We'll be painted into a corner. That's bad,
because as I've said I think we need MERGE too (just far less
urgently).
--
Peter Geoghegan
