Re: sql_drop Event Trigger - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: sql_drop Event Trigger
Date
Msg-id 20130205235802.GG5753@alvh.no-ip.org
Whole thread Raw
In response to Re: sql_drop Event Trigger  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: sql_drop Event Trigger  (Dimitri Fontaine <dimitri@2ndQuadrant.fr>)
List pgsql-hackers
Robert Haas escribió:
> On Mon, Feb 4, 2013 at 11:59 AM, Dimitri Fontaine
> <dimitri@2ndquadrant.fr> wrote:
> > Thanks. Agreed that we will have more of them. In the attached version 3
> > of the patch, it got renamed to pg_event_trigger_dropped_objects().
>
> Works for me.
>
> >> With this approach, there's no real need to introduce a new event
> >> type.  We could just make ddl_command_end triggers able to use this,
> >> and we're done.  The point of sql_drop was that it would have been
> >> called once *per dropped object*, not once per command.  But,
> >
> > Well, from the beginning of the sql_drop discussion, it's been clear
> > that it's meant to allow for users to easily attach their function to
> > any drop that might appear, whatever the command at origin of that drop.
>
> What precludes us from doing that in ddl_command_end?  ISTM we can
> just extend the ddl_command_start/end triggers to a slightly broader
> range of commands and be done with it.

I thought there was the idea that the list of objects to drop was to be
acquired before actually doing the deletion; so that the trigger
function could, for instance, get the name of the table being dropped.
I don't see that it works if we only provide
pg_event_trigger_dropped_objects to ddl_command_end events.  Am I
missing something?

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



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