After configuring a connection, Visual Explain must connect to the configured database before you can submit queries. To connect to a database, click on the arrow of the Database combo-box that is on the right side of the Visual Explain window in the Toolbar (refer to Figure 4-11).
Select a database to connect to.
A list of the databases you configured in Section 5.1 Configuring and Modifying a Database Connection appears.
Depending on whether or not Save Database Passwords is enabled (discussed in Section 5.2 Configuring Preferences), you may need to enter the database password in a pop-up window.
After this is done, if the connection is successful, the database's connection name appears in the Status Bar and the Database combo-box shows the database connection's nickname.