Please bear with a neophyte question ...
I am tempted to apply HeapTupleGetDatum to a tuple retrieved from
the syscache (as I already have code for processing a tuple presented
as a Datum).
But I see a comment on HeapTupleHeaderGetDatum: "This must *not* get
applied to an on-disk tuple; the tuple should be freshly made by
heap_form_tuple or some wrapper ..."
... and here I confess I'm unsure whether a tuple retrieved from
the syscache is more like an on-disk one, or a freshly-made one,
for purposes of the warning in that comment.
Is there a conventional proper way to pass a tuple retrieved from
syscache to code that accepts a tuple as a Datum? Or is there some
fundamental reason a smart person wouldn't do that?
Thanks,
-Chap
