Horton

Re: Fixing findDependentObjects()'s dependency on scan order (regressions in DROP diagnostic messages)

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-01-17T23:38:09Z
Lists: pgsql-hackers 
On Thu, Jan 17, 2019 at 3:20 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> > There is a symmetry to these that led me to have the same kind of
> > dependency from the index partition to the other two.
>
> It's symmetric as long as you suppose that the above are the only
> requirements.  However, there's another requirement, which is that
> if you do try to drop the index partition directly, we would like
> the error message to suggest dropping the master index, not the
> table.  The only way to be sure about what will be suggested is
> if there can be only one "owning object".

+1. This is certainly a necessary requirement. Absurd error messages
are not okay.

-- 
Peter Geoghegan

Commits

  1. Redesign the partition dependency mechanism.

  2. Fix trigger drop procedure

  3. Sort the dependent objects before recursing in findDependentObjects().

  4. Avoid sometimes printing both tables and their columns in DROP CASCADE.