Alvaro Herrera <alvherre@commandprompt.com> writes:
> Right -- I don't expect we can make use of such an idea readily. Not
> creating unnecessary pg_attribute entries for system columns is probably
> a lot easier to do.
I seem to recall having proposed that in the past, and getting shot down
on the basis that clients might be depending on those pg_attribute
entries being there. I'm not sure how big a risk there really is ---
most of the code I've seen explicitly selects attnum > 0 --- but it's a
consideration.
regards, tom lane