protected function createOrUpdateTables() {

		require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );

		$sql = "CREATE TABLE {$this->dbTable} (
				users_id INT(11) NOT null,
  				blogs_id INT(11) NOT null,
  				deleted TINYINT(1) NOT null,
  				featured INT(11) DEFAULT 0 NOT null ,
  				PRIMARY KEY  (users_id,blogs_id),
  				KEY featured (featured)
				); ";
		dbDelta( $sql );

		$sql = "CREATE TABLE {$this->dbLinkTable} (
				users_id INT(11) NOT null,
  				blogs_id INT(11) NOT null,
  				tags_id INT(11) NOT null,
  				tags_group INT(3) NOT null,
  				PRIMARY KEY  (users_id,blogs_id,tags_id,tags_group)
				); ";
		dbDelta( $sql );

		$sql = "CREATE TABLE {$this->dbTagsTable} (
				id INT(11) NOT null AUTO_INCREMENT,
  				users_id INT(11) NOT null,
  				tag VARCHAR(200) NOT null,
  				PRIMARY KEY  (id),
  				UNIQUE KEY tag (tag(191))
				); ";
		dbDelta( $sql );
	}