Horton

Re: [HACKERS] MERGE SQL Statement for PG11

Simon Riggs <simon@2ndquadrant.com>

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From: Simon Riggs <simon@2ndquadrant.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Robert Haas <robertmhaas@gmail.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: 2018-02-03T22:22:34Z
Lists: pgsql-hackers 
On 1 February 2018 at 19:39, Peter Geoghegan <pg@bowt.ie> wrote:

> Finally, I noticed a problem with your new EXPLAIN ANALYZE instrumentation:
>
> Is it 4 rows inserted, or 0 inserted?
>
> postgres=# merge into testoids a using (select i "key", 'foo' "data"
> from generate_series(0,3) i) b on a.key = b.key when matched and 1=0
> then update set data = b.data when not matched then insert (key, data)
> values (b.key, 'foo');
> MERGE 0

Got it. I'm reporting the number of rows processed instead of the
number of rows inserted. My test happened to have those values set
equal.

Minor bug, thanks for spotting.

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

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.