Re: t_self as system column

Robert Haas wrote:
> On Tue, Jul 6, 2010 at 2:49 PM, Alvaro Herrera
> <alvherre(at)commandprompt(dot)com> wrote:
>
>>
>> I'm intending to work on logical column identifiers for 9.1. Perhaps I
>> could try to have a look at this, too, while at it.
>>
>
> I have a strong suspicion that's going to be a, ahem, challenging
> project. But it would be great to have. Getting rid of the system
> column entries from pg_attribute is probably easy by comparison.
>

It will be a bit invasive, but I'm not so sure that it's difficult, just
a mass of details to take care of. Like you I'd be very glad to see it done.

> When we discussed this previously, Tom suggested that we might want to
> have a three-tiered structure: (1) permanent identifier (never
> changes, used by other system catalogs to reference the attribute in
> question), (2) display position, and (3) physical storage position.
> I'm not sure if it's feasible to think about splitting out (2) and (3)
> in a single patch, but either one would be useful by itself. Which
> are you planning to work on?
>

Why wouldn't it be feasible? In any case, having a mutable logical
column position is the feature that's been most requested.

cheers

andrew