Date: Sun, 19 Apr 2020 16:38:15 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: DETACH PARTITION and FOR EACH ROW triggers on partitioned tables
Message-ID: <20200419203815.GA825@alvherre.pgsql>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20200419191854.GA14956@telsasoft.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On 2020-Apr-19, Justin Pryzby wrote:

> It's probably rare that we'd be inserting into a table old enough to be
> detached, and normally that would be ok, but if a trigger were missing, it
> would misbehave.  In our use-case, we're creating trigger on the parent as a
> convenient way to maintain them on the partitions, which doesn't work if a
> table exists but detached..
> 
> So we'd actually prefer the behavior of indexes/constraints, where the trigger
> is preserved if the child is detached.  I'm not requesting to do that just for
> our use case, which may be atypical or not a good model, but adding our one
> data point.

I think the easiest way to implement this is to have two triggers -- the
one that's direct in the partition checks whether the table is a
partition and does nothing in that case.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services