From: Guillaume Lelarge <guillaume.lelarge@gmail.com>
To: Andrew Sullivan <ajs@crankycanuck.ca>
Cc: pgsql-sql@postgresql.org
Subject: Re: Add column and specify the column position in a table
Date: Thu, 18 May 2006 18:54:46 +0200
Message-ID: <d854adec0605180954t2f546e21u991832bca7469bef@mail.gmail.com> (raw)
In-Reply-To: <20060518155829.GE29472@phlogiston.dyndns.org>
References: <446B9418.3080700@encs.concordia.ca>
<446C0BC0.7050805@gmail.com>
<20060518140014.GA3122@surnet.cl>
<d854adec0605180843y646f953cwb490a03f3c1d0602@mail.gmail.com>
<20060518155829.GE29472@phlogiston.dyndns.org>
2006/5/18, Andrew Sullivan <ajs@crankycanuck.ca>:
> On Thu, May 18, 2006 at 05:43:19PM +0200, Guillaume Lelarge wrote:
> > Do you mean that, using "alter table test add column" with the "after"
> > option, MySQL creates a new table, populates it with the old table
> > data and finally drops the old table ? I mean, there's the same
> > performance problem with big tables ?
>
> MySQL does that for a great deal of its DDL. Yes, the performance is
> awful for this on big tables.
>
> The reason I didn't answer the OP's question, though, is that I can't
> think of a legitimate reason to do this anyway. The physical layout
> of the columns should not be of concern to the developer, who should
> be naming the columns anyway.
>
I totally agree on the physical layout. Just being curious :)
--
Guillaume.
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: guillaume.lelarge@gmail.com, ajs@crankycanuck.ca
Subject: Re: Add column and specify the column position in a table
In-Reply-To: <d854adec0605180954t2f546e21u991832bca7469bef@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox