Message-ID: <478727C3.3090301@archonet.com>
Date: Fri, 11 Jan 2008 08:24:35 +0000
From: Richard Huxton <dev@archonet.com>
User-Agent: Thunderbird 2.0.0.9 (X11/20071031)
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Alvaro Herrera <alvherre@commandprompt.com>,
	Gerardo Herzig <gherzig@fmed.uba.ar>,
	Pavel Stehule <pavel.stehule@gmail.com>, Chris Browne <cbbrowne@acm.org>,
	pgsql-sql@postgresql.org
Subject: Re: trigger for TRUNCATE?
References: <4783BEA9.3020507@fmed.uba.ar>
	<60tzloyr0u.fsf@dba2.int.libertyrms.com>
	<162867790801081338n237497efpecffaa255253274d@mail.gmail.com>
	<47864A6B.3070902@fmed.uba.ar>
	<20080110171027.GK6465@alvh.no-ip.org>
	<8003.1199986734@sss.pgh.pa.us>
	<20080110174705.GO6465@alvh.no-ip.org>
	<9563.1199992524@sss.pgh.pa.us>
In-Reply-To: <9563.1199992524@sss.pgh.pa.us>
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Tom Lane wrote:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
>> My thinking is that a TRUNCATE trigger is a per-statement trigger which
>> doesn't have access to the set of deleted rows (Replicator uses it that
>> way -- we replicate the truncate action, and replay it on the replica).
>> In that way it would be different from a per-statement trigger for
>> DELETE.
> 
> Ah, right.  I was thinking in terms of having TRUNCATE actually fire the
> existing ON DELETE-type triggers, but that's not really helpful --- you'd
> need a separate trigger-event type.  So we could just say by fiat that
> an ON TRUNCATE trigger doesn't get any rowset information, even after we
> add that for the other types of statement-level triggers.

I've always considered TRUNCATE to be DDL rather than DML. I mentally 
group it with DROP TABLE rather than DELETE>

-- 
   Richard Huxton
   Archonet Ltd