Header comments within execTuples.c state:
* - ExecutePlan() calls ExecSelect(), which passes the result slot
* to printtup(), which uses slot_getallattrs() to extract the
* individual Datums for printing.
This isn't true, though - the function ExecSelect() no longer exists.
This is because commit 8a5849b7ff24c637a1140c26fc171e45c9142005
removed it, as infrastructure for data-modifying CTEs. In fact,
ExecutePlan now directly and indifferently calls the receiveSlot.
tcop/dest stuff takes care of calling printtup(), which I guess is
what was originally intended by this comment (by which I mean, that
part probably isn't obsolete).
--
Peter Geoghegan