Forces vsql to prompt for a password before connecting to a database. The password is not displayed on the screen. This option remains set for the entire session, even if you change the database connection with the meta-command 
\connect
Establishes a connection to a new database and/or under a user name. The previous connection is closed. If dbname is - the current database name is assumed.
If username is omitted the current user name is assumed.
As a special rule, \connect without any arguments connects to the default database as the default user (as you would have gotten by starting vsql without any arguments).
If the connection attempt fails (wrong user name, access denied, etc.), the previous connection is kept if and only if vsql is in interactive mode. When executing a non-interactive script, processing immediately stops with an error. This distinction that avoids typos and a prevent scripts from accidentally acting on the wrong database.
