Re: Constraint merge and not valid status

On 2016/07/22 0:38, Robert Haas wrote:
> On Wed, Jul 13, 2016 at 5:22 AM, Amit Langote
> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> Consider a scenario where one adds a *valid* constraint on a inheritance
>> parent which is then merged with a child table's *not valid* constraint
>> during inheritance recursion. If merged, the constraint is not checked
>> for the child data even though it may have some. Is that an oversight?
>
> Seems like it. I'd recommend we just error out in that case and tell
> the user that they should validate the child's constraint first.

Agreed.

Patch attached. In addition to the recursion from parent case, this seems
to be broken for the alter table child inherit parent case as well. So,
fixed both MergeWithExistingConstraint (called from
AddRelationNewConstraints) and MergeConstraintsIntoExisting (called from
ATExecAddInherit). I had to add a new argument is_not_valid to the former
to signal whether the constraint being propagated itself is declared NOT
VALID, in which we can proceed with merging. Also added some tests for
both cases.

Thanks,
Amit