Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> >> This said, I think Hiroshi's patch seems a perfect starting point, no ?
>
> > Having phantom columns adds additional complexity to the system overall.
> > We have to decide we really want it before making things more complex
> > than they already are.
>
> I think we do, because it solves more than just the ALTER DROP COLUMN
> problem: it cleans up other sore spots too. Like ALTER TABLE ADD COLUMN
> in a table with child tables.
>
> Of course, it depends on just how ugly and intrusive the code changes
> are to make physical and logical columns distinct. I'd like to think
> that some fairly limited changes in and around heap_getattr would do
> most of the trick. If we need something as messy as the first-cut
> DROP_COLUMN_HACK then I'll look for another way...
>
Hmm,the implementation using physical and logical attribute numbers
would be much more complicated than first-cut DROP_COLUMN_HACK.
There's no simpler way than first-cut DROP_COLUMN_HACK.
I see no progress in 2x DROP COLUMN implementation.
How about giving up DROP COLUMN forever ?
Regards.
Hiroshi Inoue