(2012/02/28 23:37), Kohei KaiGai wrote:
> 2012年2月28日12:00 Shigeru Hanada<shigeru.hanada@gmail.com>:
>> We have three options:
>>
>> a) remove all system columns (posted patch)
>> b) remove system columns other than tableoid
>> c) leave all system columns as is (current 9.2dev)
>>
>> Incidentally, views, which is very similar object type to foreign
>> tables, have no system columns.
>>
>> Thoughts?
>>
> Which is the expected behavior in case of a foreign table
> is constructed as a child table of a particular regular table?
> In this case, children foreign tables don't have columns
> that exist on the parent table?
> (Although it is no matter when a regular table is a child of
> a foreign table...)
If we support table inheritance by foreign tables, foreign tables should
return something for all system columns, because a child table MUST have
all columns held by all parent tables. I'm not sure that foreign tables
should have system columns physically, like the option c).
For now, c) seems most reasonable to me.
--
Shigeru Hanada