Re: [HACKERS] MERGE SQL Statement for PG11

On Sun, Feb 4, 2018 at 5:15 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> Changes to support sub-selects don't invalidate what is there now in
> the current patch with regard to query representation or optimization.
> So support of those extra features can be added later if we choose.

I don't think you get to make a unilateral decision to exclude
features that work everywhere else from the scope of this patch.  If
there is agreement that those features can be left out of scope, then
that is one thing, but so far all the commentary about the things that
you've chosen to exclude has been negative.  Nor have you really given
any reason why they should be exempt.  You've pointed out that
parallel query doesn't handle everything (which is certainly true, but
does not mean that any feature from now and the end of time is allowed
to exclude from scope whatever seems inconvenient regardless of
contrary community consensus) and you've pointed out here and
elsewhere that somebody could go add the features you omitted later
(which is also true, but misses the general point that we want
committed patches to be reasonably complete already, not have big gaps
that someone will have to fix later).

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company