> On Mon, Nov 30, 2020 at 04:12:29PM +0300, Alexander Korotkov wrote: > > > > My first question is whether we're > > > able to handle different subscript types differently. For instance, > > > one day we could handle jsonpath subscripts for jsonb. And for sure, > > > jsonpath subscripts are expected to be handled differently from text > > > subscripts. I see we can distinguish types during in prepare and > > > validate functions. But it seems there is no type information in > > > fetch and assign functions. Should we add something like this to the > > > SubscriptingRefState for future usage? > > > > > > Datum uppertypeoid[MAX_SUBSCRIPT_DEPTH]; > > > Datum lowertypeoid[MAX_SUBSCRIPT_DEPTH]; > > > > Yes, makes sense. My original idea was that it could be done within the > > jsonpath support patch itself, but at the same time providing these > > fields into SubscriptingRefState will help other potential extensions. > > > > Having said that, maybe it would be even better to introduce a field > > with an opaque structure for both SubscriptingRefState and > > SubscriptingRef, where every implementation of custom subscripting can > > store any necessary information? In case of jsonpath it could keep type > > information acquired in prepare function, which would be then passed via > > SubscriptingRefState down to the fetch/assign. > > 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.
