Hello, sorry, it's my bad.
> 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.
I somehow misunderstood that postgres_fdw returns (xmin, xmax) =
(2, 0) but I confirmed that xmin, xmax and citd seems insane.
I completely agree with you.
Thank you for giving response for the stupid story.
regards,
--
Kyotaro Horiguchi
NTT Open Source Software Center