To save cycles, I modified create_foreignscan_plan so that it detects
whether any system columns are requested if scanning a base relation.
Also, I revised other code there a little bit.
For ExecInitForeignScan, I simplified the code there to determine the
scan tuple type, whith seems to me complex beyound necessity. Maybe
that might be nitpicking, though.
Best regards,
Etsuro Fujita