If the operation fails with SQL errors, the database user employed by your wiki (check your LocalSettings.php) probably does not have sufficient permissions.
Either grant this user additional permissions to create and delete tables, temporarily enter the login of your database root in LocalSettings.php, or use the maintenance script SMW_setup.php
which can use the credentials of an administrator.
MediaWiki:Smw smwadmin permissionswarn
From AquaPedia Case Study Database