work has to be revived.
1) In short the idea behind the Json improvements is to introduce iterators
for Json objects to extract these objects value by value, and modification
of in-memory and on-disk representations to hold partially-detoasted Json
objects (tree nodes with need-detoast state) for in-memory, and to store
key-value map in on-disk representation to extract only required values.
2) Backward compatibility would not be a problem because in on-disk
representation we could distinguish old version from new, there are enough
service bits for that. But servers not updated with this patch could not
parse new data, of course.
3) Yes, it definitely has to. These changes are very complex and invasive,
that's the reason I haven't finished the patch.
4) It doesn't seem worthy at first glance. Do you have any ideas on this?
Thank you for your interest!
