72) An instance of relational schema R (A, B, C) has distinct values of A including NULL values. Which one of the following is true

A is a candidate key

A is not a candidate key

A is a primary Key

Both (A) and (C)

Answer is:

A is not a candidate key

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74) The natural join is equal to :

Cartesian Product

Combination of Union and Cartesian product

Combination of selection and Cartesian product

Combination of projection and Cartesian product

Answer is:

Combination of selection and Cartesian product

75) Which one of the following is not true for a view:

View is derived from other tables.

View is a virtual table.

A view definition is permanently stored as part of the database.

View never contains derived columns.

Answer is:

A view definition is permanently stored as part of the database.

76) A primary key if combined with a foreign key creates

Parent-Child relationship between the tables that connect them.

Many to many relationship between the tables that connect them.

Network model between the tables that connect them.

None of the above.

Answer is:

Parent-Child relationship between the tables that connect them.

77) In E-R Diagram relationship type is represented by

Ellipse

Dashed ellipse

Rectangle

Diamond

Answer is:

Diamond

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72) An instance of relational schema R (A, B, C) has distinct values of A including NULL values. Which one of the following is true

A is not a candidate key

Databases MCQ with Answers

Related Databases MCQ with Answers

74) The natural join is equal to :

Combination of selection and Cartesian product

75) Which one of the following is not true for a view:

A view definition is permanently stored as part of the database.

76) A primary key if combined with a foreign key creates

Parent-Child relationship between the tables that connect them.

77) In E-R Diagram relationship type is represented by

Diamond

Databases MCQ with Answers