From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
cc: 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: <201901172215.plncg34crv3b@alvherre.pgsql>
References: <201901172215.plncg34crv3b@alvherre.pgsql>
Comments: In-reply-to Alvaro Herrera <alvherre@2ndquadrant.com>
	message dated "Thu, 17 Jan 2019 19:15:54 -0300"
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Content-ID: <17112.1547763927.1@sss.pgh.pa.us>
Date: Thu, 17 Jan 2019 17:25:27 -0500
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Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> On 2019-Jan-17, Tom Lane wrote:
>> DEPENDENCY_INTERNAL_AUTO, however, broke this completely, as the code
>> has no hesitation about making multiple entries of that kind.   After
>> rather cursorily looking at that code, I'm leaning to the position
>> that DEPENDENCY_INTERNAL_AUTO is broken-by-design and needs to be
>> nuked from orbit.  In the cases where it's being used, such as
>> partitioned indexes, I think that probably the right design is one
>> DEPENDENCY_INTERNAL dependency on the partition master index, and
>> then one DEPENDENCY_AUTO dependency on the matching partitioned table.

> As I recall, the problem with that approach is that you can't drop the
> partition when a partitioned index exists, because it follows the link
> to the parent index and tries to drop that.

Hm.  Still, I can't believe that it's appropriate for a partitioned index
to have exactly the same kind of dependency on the master index as it
does on the associated table.

			regards, tom lane