Horton

Re: MERGE SQL Statement for PG11

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Peter Geoghegan <pg@bowt.ie>, Michael Paquier <michael.paquier@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2017-10-30T08:44:40Z
Lists: pgsql-hackers 
On Sun, Oct 29, 2017 at 1:19 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> Nothing I am proposing blocks later work.

That's not really true.  Nobody's going to be happy if MERGE has one
behavior in one set of cases and an astonishingly different behavior
in another set of cases.  If you adopt a behavior for certain cases
that can't be extended to other cases, then you're blocking a
general-purpose MERGE.

And, indeed, it seems that you're proposing an implementation that
adds no new functionality, just syntax compatibility.  Do we really
want or need two syntaxes  for the same thing in core?  I kinda think
Peter might have the right idea here.  Under his proposal, we'd be
getting something that is, in a way, new.

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

Commits

  1. Add support for MERGE SQL command

  2. Add API of sorts for transition table handling in trigger.c

  3. Revert MERGE patch

  4. Fix several bugs related to ON CONFLICT's EXCLUDED pseudo relation.