Mikhail Gorbachev's policies of glasnost and perestroika had profound and unintended effects on the Soviet Union. In fact, many historians suggest these reforms led directly to the fall of communism and the breakup of the Soviet Union.
In SQL Server, you create a surrogate key by assigning an identity property to a column that has a number data type. A natural key is a naturally occurring descriptor of the data and one of a table's attributes that has no duplicate values. When you use a natural key as a table's primary key, each of the table's rows is uniquely identified.
Chapter 7. When a surrogate key is used in the child table in an ID-dependent relationship . a.) the parent table becomes the holder of the foreign key for the relationship. b.) the surrogate key is allowed to contain null values. c.) the surrogate key is allowed to contain non-unique values.