DBMS Q2

What is a super key?

• A set of attributes that can uniquely identify a row in a table

• A set of attributes that can uniquely identify a row in a table with no redundant attribute

• A column or group of columns used to identify a row uniquely in a table

• 
  A column or group of columns in a table that reference the primary key of another table

Which of the following statements about candidate keys is true?

• They can contain redundant attributes

• They are a set of attributes that can uniquely identify a row in a table with no redundant attribute

• They are a subset of the primary key

• They are a subset of the foreign key

What is a primary key?

• 
  A set of attributes that can uniquely identify a row in a table

• 
  A set of attributes that can uniquely identify a row in a table with no redundant attribute

• A column or group of columns used to identify a row uniquely in a table

• A column or group of columns in a table that reference the primary key of another table

What is a foreign key?

• A set of attributes that can uniquely identify a row in a table

• A set of attributes that can uniquely identify a row in a table with no redundant attribute

• A column or group of columns used to identify a row uniquely in a table

• A column or group of columns in a table that reference the primary key of another table

Which of the following is not a type of functional dependency in DBMS?

• Multivalued Dependency

• Trivial Functional Dependency

• Non-Trivial Functional Dependency

• Binary Dependency

What characterizes a transitive dependency in a database?

• 
  It is a direct relationship between values in the same table.

• 
  It is an indirect relationship between values in different tables.

• It is an indirect relationship between values in the same table.

• It does not cause a functional dependency.

What are the three types of anomalies that occur when a database is not normalized?

• Addition, Modification, Deletion

• Insertion, Update, Deletion

• Insert, Edit, Remove

• Add, Change, Delete

Which of the following statements describes a relation in 1NF (first normal form)?

• 
  It contains multi-valued attributes.

• Each attribute contains only atomic (single) values.

• 
  It contains redundant attributes.

• It allows NULL values in every attribute.

What conditions must a table satisfy to be in 2NF (second normal form)?

• It must contain multi-valued attributes.

• It must be in 1NF (first normal form) and have no non-prime attribute dependent on a proper subset of any candidate key.

• 
  It must have redundant attributes.

• It must allow NULL values in every attribute.

What conditions must a table satisfy to be in 3NF (third normal form)?

• It must contain multi-valued attributes.

• It must be in 2NF (second normal form) and have no transitive functional dependency of non-prime attribute on any super key.

• 
  It must have redundant attributes.

• 
  It must allow NULL values in every attribute.