On Mon, Nov 30, 2020 at 2:33 PM Dmitry Dolgov <9erthali...@gmail.com> wrote: > > On Fri, Nov 27, 2020 at 12:13:48PM +0300, Alexander Korotkov wrote: > > I've started to review this patch. > > Thanks! > > > 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? ------ Regards, Alexander Korotkov
