Re: Foreign table permissions and cloning

On 15 April 2011 04:26, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Why is this a documentation issue and not a code issue?  IMO we should
> flat out reject both NOT NULL and DEFAULT declarations on foreign
> tables, until such time as we're prepared to do something useful with
> them.  Reasons:

If the removal the redundant declarations is do-able for this release,
that would be preferable.  And if that change is to happen, I guess it
has to start happening immediately, letting the pgAdmin guys know too.

> 1. Accepting non-functional constraint declarations is something we've
> been heard to ridicule mysql for.  With good reason.

Fair point.

> 2. It probably won't be too long before the planner makes optimization
> decisions that assume NOT NULL declarations to be truthful.  When that
> day comes, I don't want to be seeing an exception for foreign tables in
> that logic.

Makes sense.

> 3. When we do get around to making it actually work, we will have a
> backwards-compatibility problem if prior versions accepted the
> declaration but treated it as a no-op.

Probably the most important point.

-- 
Thom Brown
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