From: Alvaro Herrera <alvherre@dcc.uchile.cl>
To: Christopher Kings-Lynne <chriskl@familyhealth.com.au>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: elein <elein@varlena.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Adding MERGE to the TODO list (resend with subject)
Date: Sun, 9 May 2004 12:09:49 -0400
Message-ID: <20040509160949.GA3897@dcc.uchile.cl> (raw)
In-Reply-To: <409DC28A.7010509@familyhealth.com.au>
References: <200405082246.i48MkTQ29755@candle.pha.pa.us>
<409D8E48.3070805@familyhealth.com.au>
<20040509035405.GA917@dcc.uchile.cl>
<409DAFEB.7020300@familyhealth.com.au>
<20040509051825.GB917@dcc.uchile.cl>
<409DC28A.7010509@familyhealth.com.au>
On Sun, May 09, 2004 at 01:32:58PM +0800, Christopher Kings-Lynne wrote:
> >>Except you can keep trying and trying without the outermost transaction
> >>failing.
> >
> >But that won't provide the necessary next key locking you mentioned in
> >your first email, will it?
>
> No, but since I can loop an infinite number of times until either the
> update or insert works, I don't need next key locking.
Oh, I see. Complex stuff ... I wonder how will it work with sequences
-- if one insertion fails and we have to try again, there's a chance a
sequence could be advanced more than once. Note the article skips the
"signal-statement" symbol (is it present in SQL99? What does it do?)
I also wonder if there will be a corresponding RULE implementation ...
The full DB2 reference is at
http://publib.boulder.ibm.com/infocenter/db2help/index.jsp?topic=/com.ibm.db2.udb.doc/admin/r0010873...
(signal-statement is something to raise an exception, apparently)
(I wonder why they don't use BNF syntax anymore ...)
--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Cuando mañana llegue pelearemos segun lo que mañana exija" (Mowgli)
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To: pgsql-sql@postgresql.org
Cc: alvherre@dcc.uchile.cl, chriskl@familyhealth.com.au, pgman@candle.pha.pa.us, elein@varlena.com, pgsql-hackers@postgresql.org
Subject: Re: Adding MERGE to the TODO list (resend with subject)
In-Reply-To: <20040509160949.GA3897@dcc.uchile.cl>
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