----- Original Message -----
From: Adam Rich
To: Sam Mason ; vinny
Cc: pgsql-general@postgresql.org
Sent: Monday, August 24, 2009 2:58 PM
Subject: Re: R: [GENERAL] Field's position in Table
From: vinny <vi...@xs4all.nl>
Subject: Re: R: [GENERAL] Field's position in Table
To: "Sam Mason" <s...@samason.me.uk>
Cc: pgsql-general@postgresql.org
Date: Monday, August 24, 2009, 2:38 PM
On Thu, 2009-08-20 at 12:16 +0100, Sam Mason wrote:
> On Thu, Aug 20, 2009 at 11:24:49AM +0200, vinny wrote:
> > I can't really think of any real reason to put the field at a
> > particular position, applications don't reallty care about the
order
> > of fields.
>
> Because it's very convenient for ad-hoc queries! PG currently
assumes
> that the column order is the same as when it was created but there
are
> (unimplemented) suggestions about how to "fix" this. See for
example:
>
> http://archives.postgresql.org/pgsql-hackers/2006-12/msg00983.php
>
> --
> Sam http://samason.me.uk/
>
But how is it convenient exactly, is it just a timesaver so you can
SELECT * instead of having to type SELECT firstname, lastname, email?
For me, saying all new fields must go at the end of the table is like
saying all new functions must go at the end of your C source file. Not that it
makes *any* difference to the end user, or other applications using your
libraries, but as developers we tend to be more organized than the general
public. Most programmers habitually organize their source code to keep related
functions together. It seems sloppy to have 10 memory-related functions
together in the source, and then an 11th hidden 6 pages down in the middle of
file-related functions. And if you're writing OO code in C++ or Java, you even
group private variables and methods separately from public ones. Most of the
people who advocate tacking new fields at the end of a table would never dream
of following this convention for source code.
So when I'm working in PgAdmin, I like to see my primary & foreign keys
listed first, then data fields in logical groupings, and finally the standard
"footer" fields we add to all tables like create & update by/date. Whenever
I'm developing and need to reference a table definition, (or do a select * in
pgAdmin for sample data) I lose productivity having to scan through all the
fields repeatedly instead of seeing at a glance the fields I want because I
know where they *should* be in the listing. Sometimes I have to scan through
the fields several times before I finally see the one I want, because it was in
the middle of unrelated items. I *never* code my applications to depend on
field order; I'm referring to development convenience only.
(Just my two cents, YMMV, etc)
Just another two cents agreeing here. I think programmers tend to be a bit anal
about this sort of thing. True, it makes no material difference but one just
tends to be more comfortable with everything nicely organized.
Bayless
