Re: How many fields in a table are too many

On Sat, Jun 28, 2003 at 01:43:32PM -0400, Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Is this a TODO?
> >     When columns can be reordered, move varlena columns to the end?
>
> I believe that really what you want is fixed-width NOT NULL columns
> first, then fixed-width nullable, then var-width.  This ordering will
> improve the odds of actually being able to use the fixed offset for
> a particular column.

This means that when you do ALTER TABLE ... SET/DROP NOT NULL the table
may have to be completely rewritten?  Altering the physical order is
sure to provoke a rewrite, but I think people will expect a change in
constraints to be a fast operation.

--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
Essentially, you're proposing Kevlar shoes as a solution for the problem
that you want to walk around carrying a loaded gun aimed at your foot.
(Tom Lane)