Re: unrecognized node type while displaying a Path due to dangling pointer

On Wed, 12 Jul 2023 at 14:23, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I did think about that, but "shallow copy a Path" seems nontrivial
> because the Path structs are all different sizes.  Maybe it is worth
> building some infrastructure to support that?

It seems a reasonable thing to have to do.  It seems the minimum thing
we could do to ensure each Path is only mentioned in at most 1
RelOptInfo.

I see GetExistingLocalJoinPath() in foreign.c might be related to this
problem, per:

> * If the inner or outer subpath of the chosen path is a ForeignScan, we
> * replace it with its outer subpath.  For this reason, and also because the
> * planner might free the original path later, the path returned by this
> * function is a shallow copy of the original.  There's no need to copy
> * the substructure, so we don't.

so that function could probably disappear if we had this.

David