Horton

Re: [HACKERS] MERGE SQL Statement for PG11

Simon Riggs <simon@2ndquadrant.com>

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From: Simon Riggs <simon@2ndquadrant.com>
To: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Peter Geoghegan <pg@bowt.ie>, Robert Haas <robertmhaas@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: 2018-03-27T08:24:49Z
Lists: pgsql-hackers 
On 26 March 2018 at 17:06, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 26 March 2018 at 15:39, Pavan Deolasee <pavan.deolasee@gmail.com> wrote:
>

> That's all I can see so far.

* change comment “once to” to “once” in src/include/nodes/execnodes.h
* change comment “and to run” to “and once to run”
* change “result relation” to “target relation”

* XXX we probably need to check plan output for CMD_MERGE also

* Spurious line feed in src/backend/optimizer/prep/preptlist.c

* No need to remove whitespace in src/backend/optimizer/util/relnode.c

* README should note that the TABLEOID junk column is not strictly
needed when joining to a non-partitioned table but we don't try to
optimize that away. Is that an XXX to fix in future or do we just
think the extra 4 bytes won't make much difference so we leave it?

* Comment in rewriteTargetListMerge() should mention TABLEOID exists
to allow us to find the correct relation, not the correct row, comment
just copied from CTID above it.

-- 
Simon Riggs                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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.