On-line schema update for a telecom database

Telecom databases need very high availability for both read and write transactions. Thus it is desired that not even schema changes are allowed to block any type of transactions. We show in this paper a method to handle schema changes which is based on a transaction oriented change with the aid of triggers. The old and the new schema can be used concurrently so it is never necessary to block any transactions. A nice feature of the method presented in this paper is that it is easy to integrate into an already existing DBMS. This functionality is rarely, if ever, found in neither products nor research articles