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Is a minimal key a candidate key?
A candidate key is a minimal super key or a super key with no redundant attribute. It is called a minimal superkey because we select a candidate key from a set of super key such that selected candidate key is the minimum attribute required to uniquely identify the table.
Which is minimal super key in DBMS?
A minimal super key is called as a candidate key. A set of minimal attribute(s) that can identify each tuple uniquely in the given relation is called as a candidate key.
What is a Superkey example?
Super Key: The set of attributes that can uniquely identify a tuple is known as Super Key. For Example, STUD_NO, (STUD_NO, STUD_NAME), etc. Adding zero or more attributes to the candidate key generates the super key. A candidate key is a super key but vice versa is not true.
What is meant by ” minimal ” key in database?
I am in the same exam as you, I have asked Paolo what is meant by this: Minimal key and candidate key determine all other attributes in a relationship. a primary key is a candidate key chosen as the smallest number of unique attributes. Thanks for contributing an answer to Database Administrators Stack Exchange!
What do you call a minimal Super key?
A candidate key is a minimal set of attributes necessary to identify a tuple; this is also called a minimal superkey.
What’s the difference between a PK and a foreign key?
Key: An attribute or combination of attributes that uniquely identify an entity/record in a relational table. PK: A single key that is unique and not-null. It is one of the candidate keys. Foreign Key: FK is a key in one table (child) that uniquely identifies a row of another table (parent).
What’s the difference between candidate key and alternate key?
Alternate Key: A candidate key that is not the primary key is called an alternate key. Candidate Key/s with Extraneous data: Consider that can be used to identify a record in the Employee table but candidate key alone is sufficient for this task. So becomes the extraneous data.