DBMS

Which of the following can not uniquely identify a record in a table

• Candidate Key
  

• Foreign Key
  

• Super Key

• 
  Primary Key

Which key is always a subset of a super key and is minimal?

• Foreign Key
  

• Composite Key

• 
  Candidate Key
  

• Alternate Key

Out of all candidate keys, other than selected keys is called:

• Super Key
  

• Primary Key
  

• Alternate Key

• 
  Foreign Key

Which of the following is not true about a Candidate key?

• Foreign key
  

• Must be unique
  

• Can not retrieve a tuple
  

• Can be composite

If a table has multiple candidate keys, then:

• All of them become primary
  

• One is chosen as primary
  

• All must be composite
  

• Only one is foreign

What is the main goal of normalization?

• To create many tables
  

• To store large data
  

• To eliminate redundancy
  

• To ensure primary key exists

Which normal form removes partial dependency?

• 1NF

• 2NF
  

• 3NF
  

• BCNF

A table is in 1NF if:

• All attributes are atomic
  

• It has a foreign key
  

• It has transitive dependency
  

• All attributes are NULL

Which normal form eliminates transitive dependency?

• 1NF
  

• 2NF
  

• 3NF
  

• BCNF

Which of the following is true for a super key?

• Always single attribute
  

• May have extra attributes
  

• Must be foreign key
  

• Cannot be candidate key