Database Redesign - Database MCQ Questions and answers- Technical Aptitude

1

Which of the following SQL statements are helpful in database redesign?

A) Correlated subqueries only B) EXISTS/NOT EXISTS expressions only C) Both of the above are helpful D) None of the above are helpful

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

2

What SQL command can be used to delete columns from a table?

A) MODIFY TABLE TableName DROP COLUMN ColumnName B) MODIFY TABLE TableName DROP ColumnName C) ALTER TABLE TableName DROP COLUMN ColumnName D) ALTER TABLE TableName DROP ColumnName

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

3

Database redesign is not terribly difficult if the:

A) database is structured. B) database is well-designed. C) database has no data. D) database is relatively small.

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

4

Which SQL-92 standard SQL command can be used to change a table name?

A) RENAME TABLE B) CHANGE TABLE C) ALTER TABLE D) None of the above is correct

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

5

The process of reading a database schema and producing a data model from that schema is known as:

A) data modeling. B) database design. C) reverse engineering. D) None of the above is correct.

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

6

Before any changes to database structure are attempted one should first:

A) clearly understand the current structure and contents of the database only. B) test any changes on a test database only. C) create a complete backup of the operational database only. D) All of the above should be done.

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

7

Which of the following modifications may not succeed?

A) Changing a column data type from char to date B) Changing a column data type from numeric to char C) Both of the above actions should succeed D) Neither of the above actions will succeed

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

8

How can you find rows that do not match some specified condition?

A) EXISTS B) Double use of NOT EXISTS C) NOT EXISTS D) None of the above is correct

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

9

A regular subquery can be processed:

A) from the top down. B) from the bottom up. C) by nesting. D) None of the above is correct.

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

10

What SQL command can be used to add columns to a table?

A) MODIFY TABLE TableName ADD COLUMN ColumnName B) MODIFY TABLE TableName ADD ColumnName C) ALTER TABLE TableName ADD COLUMN ColumnName D) ALTER TABLE TableName ADD ColumnName

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board