Add / manage an InnoDB undo tablespace

Command

CREATE UNDO TABLESPACE undo_003 ADD DATAFILE 'undo_003.ibu';

What it does

Creates a new InnoDB undo tablespace; undo logs are managed separately from data files and become truncatable.

When to use it

To manage space when long-running transactions bloat the undo log, or to move undo to a separate disk.

Caution

The file name must end in .ibu. An undo tablespace must be made inactive before it can be dropped: ALTER UNDO TABLESPACE undo_003 SET INACTIVE; then DROP UNDO TABLESPACE undo_003; This is a MySQL 8.0+ feature.