/    /  DBMS – Intro of relational database

Introduction to Relational Database


A Relational Database is a kind of database that stores, maintains and presents mutually related data points.


Let’s understand this using an example:



S.NoS. NameAge QualificationD.O.B



  • Table: A relational database has a collection of ‘Tables’ where each one is assigned to a unique name.


Example: STUDENTS in the above table.



  • Relation: ‘Relation’ is used to refer to a table.




  • Tuple: A row in a table is referred to as a ‘Tuple’.






  • Attribute: A column in a table is referred to as an ‘Attribute’.


Example: ”S.Name”



  • Domain: The set of all values in an attribute of a relation is called a ‘Domain’.


Example: [001, 04, 007, 010, 017]



  • Atomic Domain: If the elements of a domain are considered to be indivisible, then they are called ‘atomic domains’.


Ex :  [001, 04, 007, 010, 017]


Properties of Relational Database

  • The name of the relation is unique from all other relations.
  • Each relation cell contains only one atomic value.
  • Each attribute contains a definite name.
  • The attribute domain has no significance.
  • tuple has no duplicate value.
  • Order of tuples can have a unique sequence.


Reference :

Introduction to Relational DBMS.