Database Redesign - Database MCQ Questions and answers- Technical Aptitude

11

The EXISTS keyword will be true if:

A) any row in the subquery meets the condition only. B) all rows in the subquery fail the condition only. C) both of these two conditions are met. D) neither of these two conditions is met.

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Answer & Solution

Answer: Option A

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12

Changing cardinalities in a database is:

A) a common database design task. B) a rare database design task, but does occur. C) a database design task that never occurs. D) is impossible to do, so a new database must be constructed and the data moved into it.

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Answer & Solution

Answer: Option A

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13

The NOT EXISTS keyword will be true if:

A) any row in the subquery meets the condition. B) all rows in the subquery fail the condition. C) both of these two conditions are met. D) neither of these two conditions is met.

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Answer & Solution

Answer: Option B

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14

The data model that is produced from reverse engineering is:

A) a conceptual model. B) an internal model. C) a logical model. D) None of the above is correct.

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Answer & Solution

Answer: Option D

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15

To drop a column that is used as a foreign key, first:

A) drop the primary key. B) drop the table containing the foreign key. C) drop the foreign key constraint. D) All of the above must be done.

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Answer & Solution

Answer: Option C

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16

What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?

A) ALTER TABLE STUDENT ALTER CONSTRAINT GradeCheck (Grade > 0); B) ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck (Grade > 0); C) ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0); D) None of the above is correct.

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Answer & Solution

Answer: Option C

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17

Which is not true of a correlated subquery?

A) EXISTS/NOT EXISTS is a form of a correlated subquery. B) The processing of the SELECT statements is nested. C) They can be used to verify functional dependencies. D) They are very similar to a regular subquery.

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Answer & Solution

Answer: Option D

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18

A tool that can help designers understand the dependencies of database structures is a:

A) dependency graph. B) data model. C) graphical display. D) None of the above is correct.

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Answer & Solution

Answer: Option A

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19

How many copies of the database schema are typically used in the redesign process?

A) One B) Two C) Three D) Four

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Answer & Solution

Answer: Option C

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20

Because of the importance of making data model changes correctly, many professionals are ________ about using an automated process for database redesign.

A) optimistic B) skeptical C) ambivalent D) None of the above is correct

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Answer & Solution

Answer: Option B

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