Re: Avoid lost result of recursion (src/backend/optimizer/util/inherit.c)

On Wed, Dec 21, 2022 at 9:45 AM David Rowley <dgrowleyml@gmail.com> wrote:

> Also, I think it might be better to take the opportunity to rewrite
> the function to not use recursion. I don't quite see the need for it
> here and it looks like that might have helped contribute to the
> reported issue.  Can't we just write this as a while loop instead of
> having the function call itself? It's not as if we need stack space
> for keeping track of multiple parents. A child relation can only have
> 1 parent. It seems to me that we can just walk there by looping.


My best guess is that this function is intended to share the same code
pattern as in adjust_appendrel_attrs_multilevel.  The recursion is
needed as 'rel' can be more than one inheritance level below the top
parent.  I think we can keep the recursion, as in other similar
functions, as long as we make it right, as in attached patch.

Thanks
Richard