Relational Model Keys Quiz

A super key is a set of attributes that can uniquely identify a tuple, but it may contain extra attributes that are not necessary for uniqueness. A candidate key is a minimal super key, meaning it is a super key with no repeated data, and it is used to uniquely identify a record.

The key characteristics of a candidate key are: it is a minimal set of attributes that can uniquely identify a record, it must contain unique values, it can contain NULL values, and the value of the candidate key is unique and may be null for a tuple.

A candidate key is the minimal set of attributes that can uniquely identify a tuple. It must contain unique values and can contain NULL values. An example from the given text is STUD_NO in the STUDENT relation.

<p>It is important for every table to have at least a single candidate key because it is used to uniquely identify tuples(rows) in the table, and it is a fundamental requirement of the relational database model.</p> Signup and view all the answers

<p>Yes, a table can have multiple candidate keys. However, it can only have one primary key. The primary key is selected from the candidate keys to uniquely identify tuples in the table.</p> Signup and view all the answers