Tom,
DB2 supports an ALTER TABLESPACE command that allows one to add new containers to an existing tablespace. IMO, that's far more supportive of 24x7 usage.
On Wed, 21 Jun 2000 12:10:15 -0400, Tom Lane wrote:
>The right way to address this problem is to invent a "move table to
>new tablespace" command. This'd be pretty trivial to implement based
>on a file-versioning approach: the new version of the pg_class tuple
>has a new tablespace identifier in it.