Match each term to the appropriate definition. DBMS data mining hash file index key field locking protocol relation roll back schema SQL A. A means of locating a particular record within a file B. The process of extracting hidden information C. A storage system that provides efficient access to randomly chosen items D. A structural unit (with rows and columns) in a popular database model E. A system to guard against database errors due to performing transactions concurrently F. An item used to identify records uniquely G. Performs database operations requested by application software H. A popular language that implements relational database operations I. A "road map" of a particular database's design J. To "unwind" a transaction