On 2015/02/07 1:09, Tom Lane wrote:
> IIRC, this code was written at a time when we didn't have NO INHERIT check
> constraints and so it was impossible for the parent table to get optimized
> away while leaving children. So the comment in ExplainModifyTarget was
> good at the time. But it no longer is.
>
> I think your basic idea of preserving the original parent table's relid
> is correct; but instead of doing it like this patch does, I'd be inclined
> to make ModifyTable inherit from Scan not Plan, and use the scan.scanrelid
> field to carry the parent RTI. Then you would probably end up with a net
> savings of code rather than net addition; certainly ExplainModifyTarget
> would go away entirely since you'd just treat ModifyTable like any other
> Scan in this part of EXPLAIN.
Will follow your revision.
Thanks!
Best regards,
Etsuro Fujita