Re: ALTER TYPE 0: Introduction; test cases

On Sun, 2011-01-09 at 16:59 -0500, Noah Misch wrote:

> This begins the patch series for the design I recently proposed[1] for avoiding
> some table rewrites in ALTER TABLE ... ALTER COLUMN ... TYPE.  I'm posting these
> patches today:

These sound very good.

I have a concern that by making the ALTER TABLE more complex that we
might not be able to easily tell if a rewrite happens, or not.

Perhaps we should add a WITHOUT REWRITE clause? That would allow a user
to specify that they do not wish a rewrite, so if the AT requires them
to have one it would then fail.

You might point out I didn't do anything like that for my ALTER TABLE
patch, and I would agree with you. WITHOUT ACCESS EXCLUSIVE LOCK might
be an option here also.

-- Simon Riggs           http://www.2ndQuadrant.com/books/PostgreSQL Development, 24x7 Support, Training and Services