column ordering, was Re: [PATCHES] Enums patch v2

[Andrew Dunstan <andrew(at)dunslane(dot)net>]

Gregory Stark wrote:
> "Andrew Dunstan" <andrew(at)dunslane(dot)net> writes:
>
>   
> > I'm not a big fan of ordering columns to optimise record layout, except in the
> > most extreme cases (massive DW type apps). I think visible column order should
> > be logical, not governed by physical considerations.
> >     
>
> Well as long as we're talking "should"s the database should take care of this
> for you anyways.
>
>   

Sure, but the only sane way I can think of to do that would be have 
separate logical and physical orderings, with a map between the two. I 
guess we'd need to see what the potential space savings would be and 
establish what the processing overhead would be, before considering it. 
One side advantage would be that it would allow us to do the often 
requested "add column at position x".

cheers

andrew