Horton

Re: [HACKERS] MERGE SQL Statement for PG11

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Pavan Deolasee <pavan.deolasee@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Pavan Deolasee <pavan.deolasee@2ndquadrant.com>, Stephen Frost <sfrost@snowman.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-03-27T18:14:58Z
Lists: pgsql-hackers 
On Tue, Mar 27, 2018 at 1:15 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> Accepted, the only question is whether it affects UPDATE as well cos
> it looks like it should.

If you mean an UPDATE FROM self-join, then I suppose that it does, in
a very limited way. The difference is that there are no hard-coded
assumptions about the relationship between those two RTEs.

-- 
Peter Geoghegan

Commits

  1. Add support for MERGE SQL command

  2. Avoid repeated name lookups during table and index DDL.

  3. Use an MVCC snapshot, rather than SnapshotNow, for catalog scans.