What is Multivalued Attribute in DBMS?

As the name implies, multivalued attributes in DBMS contain more than one value at a time for an entity instance from a set of possible values, which is the opposite of how single-valued attributes function. Limit constraints, either upper or lower limits, may be applied to multi-valued attributes.

Curly braces {} can be used to indicate multivalued attributes inside the co-centric elliptical shape that represents these attributes.

Example:

1. Phone number of a student: Landline and mobile.
2. Email ID of a student: Personal email ID and college email ID.

What are the Problems Associated with Multivalued Attributes?

Multivalued attributes can impair the meaning of the data in the database, significantly slow down searching, and put needless limitations on the amount of data that can be recorded.

What are the Examples of Multivalued Attributes in DBMS?

There can be multiple examples of the multivalued attributes in DBMS. For example, phone number, email ID, nominee name on some insurance, dependent name, etc. we would be understanding some of the examples on details.

Example - 1: ER Model of Student A student can have multiple phone numbers. In this case, the phone number can be classified as a multivalued attribute of the student entity and these multi-valued attributes can be marked inside the co-centric elliptical shape.

Based on the above illustration, the Student entity has the following four attributes: As previously mentioned, the attributes Student_Name and Role_No are single-valued; however, the attributes Phone_No and Email_ID, which are represented by co-centric ellipses, are multi-valued. We require these attributes to be multi-valued so they may contain several values at once for an entity instance because each student in the real world can submit more than one email address and a phone number.

Learn More:

• Types of Attributes in DBMS
• Attributes in DBMS.
• ER Model in DBMS.
• Multiple Granularity in DBMS.