To: Alvaro Herrera <alvherre@commandprompt.com>
cc: 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? 
In-reply-to: <20080110174705.GO6465@alvh.no-ip.org> 
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>
Comments: In-reply-to Alvaro Herrera <alvherre@commandprompt.com>
	message dated "Thu, 10 Jan 2008 14:47:05 -0300"
Date: Thu, 10 Jan 2008 14:15:24 -0500
Message-ID: <9563.1199992524@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

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.

Never mind ...

			regards, tom lane