Re: patch: Allow \dd to show constraint comments

On Wed, Jun 29, 2011 at 12:15 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>> I was kind of hoping to avoid dealing with this can of worms with this
>> simple patch, which by itself seems uncontroversial. If there's
>> consensus that \dd and the other backslash commands need further
>> reworking, I can probably devote a little more time to this. But let's
>> not have the perfect be the enemy of the good.
>
> Patch applies clean, does what it is supposed to do, and matches other
> conventions in describe.c  Passing to committer.   pg_comments may be
> a better way to go, but that is a problem for another day...

I am inclined to say that we should reject this patch as it stands.
With or without pg_comments, I think we need a plan for \dd, and
adding one object type is not a plan. The closest thing I've seen to
a plan is this comment from Josh:

--
ISTM that \dd is best suited as a command to show the comments for
objects for which we don't have an individual backslash command, or
objects for which it's not practical to show the comment in the
backslash command.
--

If someone wants to implement that, I'm OK with it, though I think we
should also consider the alternative of abolishing \dd and just always
display the comments via the per-object type commands (e.g. \d+ would
display the table, constraint, trigger, and rule comments). I don't
want to, as Josh says, let the perfect be the enemy of the good, but
if we change this as proposed we're just going to end up changing it
again. That's going to be more work than just doing it once, and if
it happens over the course of multiple releases, then it creates more
annoyance for our users, too. I don't really think this is such a
large project that we can't get it right in one try.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company