The use of the double NOT EXISTS can be used to find rows that do not match some specified condition.

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

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

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.

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