Classification of Physical Storage Media Speed with which data can be accessed Cost per unit of data Reliability data loss on power failure or system crash physical failure of the storage device Can differentiate storage into: volatile storage:loses contents when power is switched off non-volatile storage: Contents persist even when power is switched off. Includes secondary and tertiary storage,as well as batter- backed up main-memory. Database System Concepts-5th Edition,Oct 23,2005. 11.3 @Silberschatz,Korth and SudarshanDatabase System Concepts - 5 11.3 ©Silberschatz, Korth and Sudarshan th Edition, Oct 23, 2005. Classification of Physical Storage Media Speed with which data can be accessed Cost per unit of data Reliability data loss on power failure or system crash physical failure of the storage device Can differentiate storage into: volatile storage: loses contents when power is switched off non-volatile storage:  Contents persist even when power is switched off.  Includes secondary and tertiary storage, as well as batter￾backed up main-memory