From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
cc: Amit Langote <amitlangote09@gmail.com>, Peter Geoghegan <pg@bowt.ie>,
        PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Fixing findDependentObjects()'s dependency on scan order
 (regressions in DROP diagnostic messages)
In-reply-to: <20190209174123.GA6498@alvherre.pgsql>
References: <20190209174123.GA6498@alvherre.pgsql>
Comments: In-reply-to Alvaro Herrera <alvherre@2ndquadrant.com>
	message dated "Sat, 09 Feb 2019 14:41:23 -0300"
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Date: Sat, 09 Feb 2019 15:26:55 -0500
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Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2019-Feb-09, Tom Lane wrote:
>> Well, the question that's begged here is exactly why it's okay to remove
>> the trigger and dependency link despite the fact that the constraint needs
>> it.  I suppose the answer is that we'll subsequently insert a new trigger
>> implementing the same constraint (and internally-linked to it)?  That
>> information is what I'd like to have in the comment.

> Well, the answer is that the trigger is no longer needed.  This is an
> action trigger, i.e. it's attached to the referenced relation; and the
> action is making an independent table become a partition.  Since the
> partition is reachable by the action trigger that goes through the
> parent table, we no longer need the action trigger that goes directly to
> the partition.

Oh ... then why don't we go ahead and get rid of the constraint entry,
too?

			regards, tom lane