Re: Column storage positions

On Wed, 2007-02-21 at 16:57 -0300, Alvaro Herrera wrote:
> Andrew Dunstan escribió:
> > Simon Riggs wrote:
> > >
> > >I agree with comments here about the multiple orderings being a horrible
> > >source of bugs, as well as lots of coding even to make it happen at all
> > >http://archives.postgresql.org/pgsql-hackers/2006-12/msg00859.php
> >
> > I thought we were going with this later proposal of Tom's (on which he's
> > convinced me):
> > http://archives.postgresql.org/pgsql-hackers/2006-12/msg00983.php - if
> > not I'm totally confused (situation normal). The current thread started
> > with this sentence:
> >
> > >Inspired by this thread [1], and in particular by the idea of storing
> > >three numbers (permanent ID, on-disk storage position, display
> > >position) for each column, I spent a little time messing around with a
> > >prototype implementation of column storage positions to see what kind
> > >of difference it would make.
> >
> > I haven't understood Alvaro to suggest not keeping 3 numbers.
>
> Right, I'm not advocating not doing that -- I'm just saying that the
> first step to that could be decoupling physical position with attr id
> :-) Logical column ordering (the order in which SELECT * expands to)
> seems to me to be a different feature.

Not disagreed. :-)

Something very, very simple seems most likely to be an effective
additional feature for 8.3. We can implement the 2/3 position version
for 8.4

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com