Draw a diagram that illustrates the position of the Database Management System Interface in relation to the Database Management System Kernel and Database Management System Toolkit.
Briefly describe the recovery facilities provided by most DBMS.
There is usually a module which provides:
- A mechanism which enables backup copies of either the whole or part of a database to made on a regular basis.
- A transaction log which automatically records execution of transactions. Transaction log records contain: log record ID, time, date, operation type, data values before and after changes, checkpoint records.
- A facility for check pointing updates to a database, involves force writing database buffers to secondary storage at pre-determined intervals.
- A facility which permits the system to restore the database to a consistent state after hardware and software failure.