What is a RDBMS (Relational Database Management System )?

RDBMS stands for Relational Database management System. It is a database management system that is based on the relational model introduced by E.F Codd in 1970s. In relational model, data is stored in relations (tables) and is represented in form of tuples (rows).

RDBMS is used to manage Relational database. Relational database is a collection of organized set of tables related to each other, and from which data can be accessed easily. In a relational database, relationships between data items are expressed by means of tables.

All modern database management systems like MySQL, Microsoft SQL Server, IBM DB2, ORACLE and Microsoft Access are based on RDBMS.

RDBMS uses Structured Query Language (SQL) to access the data in the database.

RDBMS Terminologies:

Relation:

Relational databases store data or information in tables. In Relational database model, tables are referred as “relations”. A table is similar to a spreadsheet where data is stored in rows and columns. A table refers to a two dimensional representation of data using rows and columns.

Tuple:

Each of the rows of data in a relation (table) is called a tuple. Every tuple in the relation represents a collection of related data values.  

Attribute: 

The columns of a relation are called attributes which are also referred as fields. A relation consists of several tuples or records, each record can be broken down into several smaller parts of data known as Attributes.

Domain:

Domain of an attribute refers to the set of all the possible values for that attribute. It is the collection (set) of possible values from which the value for a column is derived.

Degree: 

The total number of attributes in a relation is called the degree of the relation.

Cardinality:

The total number of tuples present in a relation is called the cardinality of the relation.

Advantages of RDBMS:

 Following are the benefits or advantages of RDBMS:

1. It is easy to use.

2. It is secured in nature.

3. The data manipulation can be done.

4. It limits redundancy and replication of the data.

5. It offers better data integrity.

6. It provides better physical data independence.

7. It offers logical database independence i.e. data can be viewed in different ways     by the different users.

8. It provides better backup and recovery procedures.

9. It provides multiple interfaces.

10. Multiple users can access the database which is not possible in DBMS.