Re: Doc: fix the rewrite condition when executing ALTER TABLE ADD COLUMN

On Tue, Dec 3, 2024 at 3:13 AM Masahiro Ikeda <ikedamsh(at)oss(dot)nttdata(dot)com> wrote:
>
> Hi,
>
> The documentation seems to overlook the rewrite condition
> when executing ALTER TABLE ADD COLUMN.
>
> The current document states that a volatile DEFAULT will
> trigger a rewrite of the table and its indexes. However, the
> table and its indexes will also be rewritten when an IDENTITY
> column is added, or when a column with a domain data type that
> has constraints is added.
>
> What do you think?
>

We still see a number of people asking (or confused) about table
rewrites when adding columns, so I think the initial tip should
remain, though I think it can be cleaned up a little.

In the second section (alter_table.sgml) I liked the idea of adding
these additional examples, though I tweaked the wording a bit to
(hopefully) make it a little easier to read.

Modified patch attached.

Robert Treat
https://xzilla.net