Re: ALTER TABLE DROP COLUMN

The Hermit Hacker wrote:
>
> On Mon, 9 Oct 2000, Bruce Momjian wrote:
>
> Ya, but in one email, you appear to agree with me ... then Tom posts a
> good point and you jump over to that side ... at least pick a side? :) I
> too wish to see it implemented, I just don't want to have to double my
> disk space if at some point I decide to upgrade an application and find
> out that they decided to change their schema(s) :(

As Don already pointed out, if you don't have enough room to double your
table size you must be running an one-table, append-only application where
you can only do a very limited set of queries.

select * from that_table order by some_column_without_an_index; is definitely
out as it takes many times the space of a that_table anyway.

There _may_ be some cases where 2x is unacceptable, but without radically
changing tables on-disk structure there is no way to avoid it and still be
able to rollback or even crash cleanly ;)

-----------------
Hannu