SQL*Plus is a tool used to enter SQL commands and display the output. It is provided with every Oracle installation, whether on Windows, Unix, or Linux. It is a command line interface and supports editing, user input, and report formatting. In 11g, SQL*Plus for Windows (sqlplusw.exe) is no longer part of the client or database install.
The command line version (sqlplus.exe) is still available. You can use an older version of SQL*Plus for Windows to connect to an 11g database, but some functionality may not be supported. SQL Developer is a GUI interface that is shipped with 11g and should be considered the replacement for SQL*Plus for Windows.
To start SQL*Plus, simply type ‘sqlplus’ at the command prompt or after starting a DOS command session in Windows. Under normal circumstances, SQL*Plus prompts you for a username and corresponding password. If you are able to provide a valid username/password combination, the SQL> prompt appears on your screen to indicate that you have successfully established a session.
You can also start SQL*Plus with the username and password at the command line, as shown in Figure 2-4.
In this case, if the username/password are valid, the SQL> prompt will appear. If not, you will be asked to enter a valid
username and password.