Re: DROP COLUMN

On Wed, 2002-07-17 at 11:29, Christopher Kings-Lynne wrote:
> > > But those (few) apps that still need intimate knowledge about postrges'
> > > internals will always have to query the original system _tables_.
> > >
> > > Also, as we have nothing like Oracles ROWNR, I think it will be quite
> > > hard to have colnums without gaps in the system views,
> >
> > Agreed. However do we have to give up all views which omit
> > dropped columns ?
>
> What's Oracle's ROWNR?

A pseudocolumn that is always the number of row as it is retrieved.

so if we had it, we could do something like

select
ROWNUM as attlognum,
attname
from (
select attname
from pg_attribute
where attrelid = XXX
and attisdropped
order by attnum
) att
order by attlognum;

and have nice consecutive colnums

the internal select is needed because ROWNUM is generated in the
executor as the tuple is output, so sorting it later would mess it up

-------------
Hannu