DBMS Keys Quiz 3

The primary key of a weak entity needs to be formed. It is known as the:

• Discriminator or partial key

• Foreign Key

• Weak Key

• Strong Key

A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.

• Rows

• Key

• Attribute

• Field

The subset of a super key is a candidate key under what condition?

• No proper subset is a super key

• All subsets are super keys

• Subset is a super key

• Each subset is a super key

Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?

• Candidate key

• Sub key

• Super key

• Foreign key

Which one of the following cannot be taken as a primary key?

• Id

• Register number

• Dept_id

• Street

An attribute in a relation is a foreign key if the _______ key from one relation is used as an attribute in that relation.

• Candidate

• Primary

• Super

• Sub

The relation with the attribute which is the primary key is referenced in another relation. The relation which has the attribute as a primary key is called

• Referential relation

• Referencing relation

• Referenced relation

• Referred relation

A combination of two or more columns used to identify particular rows in a relation is a(n) _____ .

• record

• field

• composite key

• foreign key

An attribute (or combination of attributes) used strictly for data retrieval purposes is called a ___________

• super key

• candidate key

• secondary key

• primary key

Can we define more than one primary key in a table?

• Yes

• No