Joe Conway <mail(at)joeconway(dot)com> writes:
> Just for reference, what is arg[i] if it isn't a (TupleTableSlot *)
> anymore -- is it just a HeapTuple?
No, it's a HeapTupleHeader pointer. You need to reconstruct a HeapTuple
on top of that to work with heap_getattr and most other core backend
routines. Also don't forget to ensure that you detoast the datum;
this is not useful at the moment but will be important Real Soon Now.
I added standard argument-fetch macros to fmgr.h to help with the
detoasting bit.
regards, tom lane