Re: Column storage positions

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.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support