Physical security is not as important as technical security

The _______________________ puzzle is a favorite of computer scientists because of its elegant recursive solution.

a) Tower of Hanoi b) Sudoku c) Tetris d) Tic-Tac-Toe e) none of the above

To indicate columns that cannot contain null values, use the ____________________ clause in a CREATE TABLE statement.

Fill in the blank(s) with the appropriate word(s).