Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> writes:
> Hello, I found that tuples come from file_fdw has strange xmin and xmax.
file_fdw isn't documented to return anything useful for xmin/xmax/etc,
so I don't find this surprising.
> The patch attached fixes the header of materialized tuple to be
> sane (2, 0) if the source slot was a virtual tuple in mechanism().
I don't really think it's ForeignNext's place to be doing something
about this. It seems like a useless expenditure of cycles. Besides,
this fails to cover e.g. postgres_fdw, which is likewise unconcerned
about what it returns for system columns other than ctid.
regards, tom lane
