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: 2018-03-27T11:30:54Z
Lists: pgsql-hackers 
On 27 March 2018 at 11:46, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 27 March 2018 at 10:31, Pavan Deolasee <pavan.deolasee@gmail.com> wrote:
>
>> Fixed in v26.
>
> More comments on v26

In terms of further performance optimization, if there is just one
WHEN AND condition and no unconditional WHEN clauses then we can add
the WHEN AND easily to the join query.

That seems like an easy thing to do for PG11

-- 
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.