Re: ALTER COLUMN/logical column position

Hannu Krosing <hannu@tm.ee> writes:
> You are just shifting the interface problems to a place needing way more
> changes in the backend. There will be some problems either way.

Exactly.  I'm considerably more worried about breaking out-of-the-way
places in the backend than I am about what order someone's admin tool
presents the columns in.

> Btw, most of these concerns (and more) were already iterated when DROP
> column was done causing gaps in attnum. There were a lot of doomsday
> profecies, but in the end it went quite smoothly.

That is a good comparison point.  I'm inclined to think that we should
do it in a way that minimizes backend changes.  The way to do that is
to keep attnum with its current definition (physical position) and add
a new column for the logical position, which only a small number of
places will need to care about.
        regards, tom lane