The Mnesia DBMS runs in the same adress space as the application owning the data, yet the application cannot destroy the contents of the data base. This provides for both fast accesses and efficient fault-tolerance, normally conflicting requirements. The implementation is based on features in the Erlang programming language, in which Mnesia is embedded. 1 Introduction The management of data in telecommunications system has many aspects whereof some, but not all, are addressed by traditional commercial DBMSs (Data Base Management Systems). In particular the very high level of fault tolerance which is required in many non-stop systems, combined with requirements on the DBMS to run in the same address space as the application, have led us to implement a brand new DBMS. This paper describes the motivation for, as well as the design of this new DBMS, called Mnesia. Mnesia is implemented in, and very tightly connected to, the programming language Erlang and it provides the functionality tha...

Mnesia is a full DBMS made for telecommunications industrial needs. It has distributed transactions, fast real time lookups, crash recovery and a logical query language. The DBMS is written in the functional language Erlang which is also the intended applications language. It already has real users developing products. 1 Introduction Mnesia is a multiuser Distributed DBMS (Database Management System) specially made for industrial telecommunications applications written in the symbolic language Erlang[AVWW95]. In telecommunications applications there are needs different from the features provided by traditional DBMS's. The applications we now see implemented in the Erlang language need a mixture of a broad range of features. The most extreme among those are: 1. fast soft real-time key-value lookup 2. complicated non-realtime queries mainly for operation and maintenance 3. distributed data due to distributed applications 4. high fault-tolerance 5. dynamic re-configuration 6. variable-...