What is minimal super key in DBMS?
In the relational data model a superkey is a set of attributes that uniquely identifies each tuple of a relation. A candidate key (or minimal superkey) is a superkey that can’t be reduced to a simpler superkey by removing an attribute.
Which is called minimal super 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.
What is Superkey in database?
What is a Super key in SQL? Super key is a single key or a group of multiple keys that can uniquely identify tuples in a table. Super Key can contain multiple attributes that might not be able to independently identify tuples in a table, but when grouped with certain keys, they can identify tuples uniquely.
What is super key in database with 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 are minimal keys?
a primary key is a candidate key chosen as the smallest number of unique attributes. He states that a minimal key is the fewest number of attributes so he means a primary key when he says minimal.
Is primary key a minimal superkey?
Primary Key is a minimal set of attribute (or set of attributes) that is used to uniquely identifies all attributes in a relation. 2. All super keys can’t be primary keys. Primary key is a minimal super key.
Is minimal super key Mcq?
Concept: Superkey is a set of attributes within a table whose values can be used to uniquely identify a tuple. A candidate key is a minimal superkey.
Is primary key a Superkey?
Super Key is an attribute (or set of attributes) that is used to uniquely identifies all attributes in a relation. Primary Key is a minimal set of attribute (or set of attributes) that is used to uniquely identifies all attributes in a relation. Primary key is a minimal super key.
What is the minimal super key Mcq?
candidate key
Concept: Superkey is a set of attributes within a table whose values can be used to uniquely identify a tuple. A candidate key is a minimal superkey.
How do you identify a super key?
A super key is any combination of columns that uniquely identifies a row in a table. A candidate key is a super key which cannot have any columns removed from it without losing the unique identification property. This property is sometimes known as minimality or (better) irreducibility.
What is the minimal primary key?