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.
To see the commands as SQL*Plus enters them, you can SET ECHO ON. The ECHO system variable controls the listing of the commands in scripts run with the START, @ and @@ commands. Setting the ECHO variable OFF suppresses the listing. START, @ and @@ leave the last SQL command or PL/SQL block of the script in the buffer.ollow the SQLPLUS command with your username, a slash, your password, a space, @, and the name of the file: SQL*Plus starts and runs the script. Include your username, a slash (/), and your password as the first line of the file.