Database Management System
CHARACTERISTICS OF DATA IN A DATABASE
The data in a database should have the following features.
Shared
Persistence
Validity / Integrity / Correctness
Security
Consistency
Non-redundancy
Independence
Shared
Persistence
Validity / Integrity / Correctness
Security
Consistency
Non-redundancy
Independence
Shared
Data in a database are shared among different users and applications
Persistence
Data in a database exists permanently in the sense that the data can live beyond the scope of the process that created it.
Validity / Integrity / Correctness
Data should be correct with respect to the real world entity that they represent.
Security
Data should be protected from unauthorized access.
Consistency
Whenever more than one data element in a database represents related real world values, the values should be consistent with respect to the relationship.
Non-redundancy
No two data items in a database should represent the same real-world entity.
Independence
The three levels in the schema (internal, conceptual and external) should be independent of each other so that the changes in the schema at one level should not affect the other levels.