Re: creating CHECK constraints as NOT VALID

On 1 June 2011 23:47, Alvaro Herrera <alvherre@commandprompt.com> wrote:
>
> Here's a complete patch with all this stuff, plus doc additions and
> simple regression tests for the new ALTER DOMAIN commands.
>
>    Enable CHECK constraints to be declared NOT VALID
>
>    This means that they can initially be added to a large existing table
>    without checking its initial contents, but new tuples must comply to
>    them; a separate pass invoked by ALTER TABLE / VALIDATE can verify
>    existing data and ensure it complies with the constraint, at which point
>    it is marked validated and becomes a normal part of the table ecosystem.
>

I think that you also need to update the constraint exclusion code
(get_relation_constraints() or nearby), otherwise the planner might
exclude a relation on the basis of a CHECK constraint that is not
currently VALID.

Regards,
Dean