Re: Odd system-column handling in postgres_fdw join pushdown patch

On 2016/04/14 12:04, Etsuro Fujita wrote:
> On 2016/04/14 4:57, Robert Haas wrote:
>> 2. When a join is pushed down, deparse system columns using something
>> like "CASE WHEN r1.* IS NOT NULL THEN 0 END", except for the table OID
>> column, which gets deparsed with the table OID in place of 0.  This
>> delivers the correct behavior in the presence of outer joins.

> I think that that would cause useless data transfer for such culumns.
> Why not set values locally for such columns?

At least for the table OID.

Best regards,
Etsuro Fujita