Database Redesign MCQs

Question 1

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

Accepted Answer

Both of the above are helpful

Answer

Correlated subqueries only

Answer

EXISTS/NOT EXISTS expressions only

Answer

None of the above are helpful

Question 2

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

Accepted Answer

ALTER TABLE TableName DROP COLUMN ColumnName

Answer

MODIFY TABLE TableName DROP COLUMN ColumnName

Answer

MODIFY TABLE TableName DROP ColumnName

Answer

ALTER TABLE TableName DROP ColumnName

Question 3

Database redesign is not terribly difficult if the:

Accepted Answer

database has no data.

Answer

database is structured.

Answer

database is well-designed.

Answer

database is relatively small.

Question 4

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

Accepted Answer

None of the above is correct

Answer

RENAME TABLE

Answer

CHANGE TABLE

Answer

ALTER TABLE

Question 5

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

Accepted Answer

reverse engineering.

Answer

data modeling.

Answer

database design.

Answer

None of the above is correct.

Question 6

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

Accepted Answer

All of the above should be done.

Answer

clearly understand the current structure and contents of the database only.

Answer

test any changes on a test database only.

Answer

create a complete backup of the operational database only.

Question 7

Which of the following modifications may not succeed?

Accepted Answer

Changing a column data type from char to date

Answer

Changing a column data type from numeric to char

Answer

Both of the above actions should succeed

Answer

Neither of the above actions will succeed

Question 8

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

Accepted Answer

Double use of NOT EXISTS

Answer

EXISTS

Answer

NOT EXISTS

Answer

None of the above is correct

Question 9

A regular subquery can be processed:

Accepted Answer

from the bottom up.

Answer

from the top down.

Answer

by nesting.

Answer

None of the above is correct.