Re: Smartest way to resize a column?

On Sunday 11 January 2009 5:07:31 pm Phoenix Kiula wrote:
> I am trying to resize a column on a large-ish database (with 5 million
> rows).
>
> The column was 20 characters before, now I want to make it 35 characters.
>
> Challenge is: this is the main indexed column in a busy database.
>
> I tried looking at the ALTER TABLE commands available and there seems
> nothing that allows me to simply change column size from varchar(20)
> to varchar(35)?
>
> So I have this in mind:
>
>
>   BEGIN;
>   ALTER TABLE users ADD COLUMN name_new varchar(35);
>   UPDATE users SET name_new = name;
>   ALTER TABLE users DROP COLUMN name;
>   ALTER TABLE users RENAME COLUMN name_new TO name;
>   COMMIT;
>
>
> I guess this would work, but I am wondering if there is a nicer way to
> do this that doesn't involve a new column, copying, then dropping old
> column?
>
> Thanks!

ALTER TABLE users ALTER COLUMN name_new TYPE varchar(35)

--
Adrian Klaver
aklaver@comcast.net