> On Wed, Dec 02, 2020 at 11:52:54AM -0500, Tom Lane wrote:
> Dmitry Dolgov <9erthalion6@gmail.com> writes:
> >> On Mon, Nov 30, 2020 at 02:26:19PM +0100, Dmitry Dolgov wrote:
> >>> On Mon, Nov 30, 2020 at 04:12:29PM +0300, Alexander Korotkov wrote:
> >>> The idea of an opaque field in SubscriptingRef structure is more
> >>> attractive to me. Could you please implement it?
>
> >> Sure, doesn't seem to be that much work.
>
> I just happened to notice this bit. This idea is a complete nonstarter.
> You cannot have an "opaque" field in a parsetree node, because then the
> backend/nodes code has no idea what to do with it for
> copy/compare/outfuncs/readfuncs. The patch seems to be of the opinion
> that "do nothing" is adequate, which it completely isn't.
>
> Perhaps this is a good juncture at which to remind people that parse
> tree nodes are read-only so far as the executor is concerned, so
> storing something there only at execution time won't work either.
Oh, right, stupid of me. Then I'll just stick with the original
Alexanders suggestion.