Understanding an Attribute in a Relation

What is an Attribute?

An attribute is an elementary property describing an object or entity. An attribute is a characteristic of a relation in a relational database. Each attribute is a column in the relation that describes an object or entity. It is a piece of information associated with a record in a relation.

Types of Attributes

Attributes can be divided into three types: regular, composite and derived. Regular attributes are those that are directly associated with a relation and are stored in the relation itself. Composite attributes are those that are composed of two or more regular attributes. Derived attributes are those that can be derived from other attributes.

How are Attributes Used?

Attributes are used to store information about entities in a relation. They are used to identify, store, and retrieve data from a relation. Attributes can also be used for filtering and sorting data, as well as for forming relationships between entities. For example, if a relation contains a customer table, the customer’s name and address can be stored as attributes in the customer table.

Example of an Attribute

As an example, consider a relation that contains a table of students. The attributes of the student table might include the student’s name, address, phone number, age, and grade point average (GPA). The name attribute would be a regular attribute, while the GPA attribute would be a derived attribute.

Conclusion

An attribute is an elementary property describing an object or entity. It is a column in the relation that describes an object or entity. Attributes are used to store information about entities in a relation, and can also be used for filtering and sorting data, as well as for forming relationships between entities. Examples of attributes include name, address, phone number, age, and grade point average.