Horton

Re: SQL design pattern for a delta trigger?

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Richard Broersma Jr <rabroersma@yahoo.com>
Cc: Vivek Khera <khera@kcilink.com>, Colin Wetherbee <cww@denterprises.org>, Ted Byers <r.ted.byers@rogers.com>, pgsql-general@postgresql.org
Date: 2007-12-11T02:10:19Z
Lists: pgsql-general 
Richard Broersma Jr wrote:
> --- On Mon, 12/10/07, Ted Byers <r.ted.byers@rogers.com> wrote:
> 
> > but how do you
> > do it using SQL in an RDBMS?  
> 
> I believe that there is an ANSI SQL command "MERGE" that is yet to be implemented into PostgreSQL.

IIRC the standard's definition of MERGE is still subject to the race
condition :-)  It seems mostly defined for OLAP, and assumes rather
static data.

-- 
Alvaro Herrera                 http://www.amazon.com/gp/registry/DXLWNGRJD34J
"La tristeza es un muro entre dos jardines" (Khalil Gibran)