When the last-chance threshold on the master database is reached, you can use alter database to add space to the master database’s transaction log. This allows more activity in the server by causing suspended transactions in the log to become active. However, while the master transaction log is at its last-chance threshold, you cannot use alter database to make changes in other databases. Thus, if both master and another database reach their last-chance thresholds, you must first use alter database to add log space to the master database, and then use it again to add log space to the second database.
