Answers:
Misuse of database can be categorized as being either intentional or accidental.
Accidental loss of data consistency:
1. System crashes during transaction processing
2. Due to multi-users accessing the database.
3. Distribution of data over several computers.
Intentional loss of data may be due to reading, writing or destruction of data by unauthorized users.
Database security usually protects data by several techniques.
Certain portion [selected columns] of a database is available only to those persons who are authorized to access it. This ensures that the confidentiality of data is maintained.
For e.g.: In large organizations, where different users may use the same database, sensitive information such as employees’ salaries should be kept confidential from most of the other users.
To protect database we must take security measures at several levels. Network security is also important as database security.