Sometimes it is desired to bring a database back to a previous state (for many reasons, e.g., cases when the database is found corrupted due to a software error, or if it has been updated with erroneous data). To achieve this a backup operation is done occasionally or continuously, where each desired database state (i.e., the values of its data and their embedding in database's data structures) is kept within dedicated backup files (many techniques exist to do this effectively). When this state is needed, i.e., when it is decided by a database administrator to bring the database back to this state (e.g., by specifying this state by a desired point in time when the database was in this state), these files are utilized to restore that state. COUNT 4
QSN1 Name a reason to take a database backward in time? ANS1 database is found corrupted QSN2 Is each database backup kept in the same file? ANS2 dedicated backup files QSN3 Who can restore a database that has been corrupted? ANS3 database administrator QSN4 What parameter is requiret to restore a database? ANS4 desired point in time