Basically, relational databases are based on relational set theory. Normalization is a vital component of relational model of databases. Relational operations, supported by the relational databases work best with normalized tables. A relational database supports relational algebra, consequently supporting the relational operations of the set theory. Apart from mathematical set operations namely, union, intersection, difference and Cartesian product, relational databases also support select, project, relational join and division operations. These operations are unique to relational databases.
Relational databases support an important concept of dynamic views. In a relational database, a view is not a part of the physical schema, it is dynamic. Hence changing the data in a table alters the data depicted by the view. Views can subset data, join and simplify multiple relations, dynamically hide the complexity in the data and reduce the data storage requirements.
Relational databases use SQL, which is an easy and human-readable language. SQL instructions are in the form of plain instructions, which can be put to the database for implementation. Most of the database vendors support the SQL standard. A competitive technology of flat files supports a sequential storage of data and fails to provide the users with search and query options. On the other hand, relational databases provide the users with simple operations to manipulate data in the databases and retrieve it. Moreover relational databases establish defined relationships between the tables, thus giving their users a complete picture of the data stored.
Relational databases have an excellent security. A relational database supports access permissions, which allow the database administrator to implement need-based permissions to the access of the data in database tables. Relational databases support the concept of users and user rights, thus meeting the security needs of databases. Relations are associated with privileges like create privilege, grant privilege, select, insert and delete privileges, which authorize different users for corresponding operations on the database.
The other important advantages of relational databases include their performance, power, and support to new hardware technologies as also flexibility and a capacity to meet all types of data needs. Relational databases are scalable and provide support for the implementation of distributed systems.
Owing to their advantages and application in the operations of data storage and retrieval of the modern times, relational databases have revolutionized database management systems.
Relational databases support an important concept of dynamic views. In a relational database, a view is not a part of the physical schema, it is dynamic. Hence changing the data in a table alters the data depicted by the view. Views can subset data, join and simplify multiple relations, dynamically hide the complexity in the data and reduce the data storage requirements.
Relational databases use SQL, which is an easy and human-readable language. SQL instructions are in the form of plain instructions, which can be put to the database for implementation. Most of the database vendors support the SQL standard. A competitive technology of flat files supports a sequential storage of data and fails to provide the users with search and query options. On the other hand, relational databases provide the users with simple operations to manipulate data in the databases and retrieve it. Moreover relational databases establish defined relationships between the tables, thus giving their users a complete picture of the data stored.
Relational databases have an excellent security. A relational database supports access permissions, which allow the database administrator to implement need-based permissions to the access of the data in database tables. Relational databases support the concept of users and user rights, thus meeting the security needs of databases. Relations are associated with privileges like create privilege, grant privilege, select, insert and delete privileges, which authorize different users for corresponding operations on the database.
The other important advantages of relational databases include their performance, power, and support to new hardware technologies as also flexibility and a capacity to meet all types of data needs. Relational databases are scalable and provide support for the implementation of distributed systems.
Owing to their advantages and application in the operations of data storage and retrieval of the modern times, relational databases have revolutionized database management systems.
