Functions of connect to php with postgresql database

    * pg_pconnect() - Open a PostgreSQL connection same as mysql_connect()
    * pg_close() - Closes PostgreSQL database connection same as mysql_close()
    * pg_host() - Returns host name associated with the connection
    * pg_port() - Return port number associated with the connection
    * pg_tty() - Return TTY name associated with the connection
    * pg_options() - Get options associated with the connection
    * pg_dbname() - Get a database name same as mysql_select_db()