Final answer:
The closure of attributes in a database system is important for determining the key of a relation and ensuring data integrity by correctly specifying dependencies during the normalization process.
Step-by-step explanation:
The concept of closure of attributes is important in the field of database systems, specifically in relational database design. The closure of a set of attributes under a set of functional dependencies is the set of attributes that can be functionally determined from it. This concept is critical when determining the key for a relation in a database. By finding the closure, we can identify all attributes dependent on a given set of attributes and ensure that we're capturing all necessary data dependencies appropriately. In essence, it confirms the sufficiency of a candidate key.
For example, the closure helps to maintain the integrity of data by specifying the relationships and dependencies correctly, which is vital to the normalization process. Normalization aims to reduce redundancy and improve data integrity. Therefore, understanding the closure of attributes is quintessential in building a robust and well-structured database.