Andres Freund <andres@anarazel.de> writes:
> Since we already have CustomScan->methods, it seems to be rather
> reasonable to have a CopyCustomScan callback and let it do the copying
> of the private data if present? Or possibly of the whole node, which'd
> allow to embed it into a bigger node?
Weren't there rumblings of requiring plan trees to be deserializable/
reserializable, not just copiable, so that they could be passed to
background workers? Not that I'm particularly in favor of that, but if
you're going to go in the direction of allowing private data formats to be
copied then I think you're likely to have to address the other thing.
In any case, since this convention already exists for FDWs I'm not
sure why we should make it different for CustomScan.
regards, tom lane