Complex Attribute
- When multi-valued and composite attributes together form an attribute then it is called a Complex attribute.
- Complex attributes can have an unlimited number of sub-attributes.
Example
- Here for the student, we created an attribute named contact_info which further decomposed into phone_no + Address.
- The address is a composite attribute which is further divided into simple attributes and phone_no is a multivalued attribute.
- This indicates that the contact_info attribute is made from the multi-valued and composite attribute.
- This type of attribute is known as the Complex Attribute.
Attributes in DBMS
Attributes are properties or characteristics of an entity. Attributes are used to describe the entity. The attribute is nothing but a piece of data that gives more information about the entity. Attributes are used to distinguish one entity from the other entity. Attributes help to categorize the entity and the entity can be easily retrieved and manipulate the entity. Attributes can help the database to be more structural and hierarchical. An entity with no attribute is of no use in the database.