Oracle Database -- Connecting Remotely to a Restrcted Database

Problem

You are trying to connect remotely to a database which is opened in the restricted mode. You get error:

ORA-12526: TNS:listener: all appropriate instances are in restricted mode

Solution

Add UR=A to your TNS entry. For example,

 <service_name>=
  (DESCRIPTION=
    (ADDRESS=
      (PROTOCOL=TCP)
      (HOST=<host_name>)
      (PORT=1521)
    )
    (CONNECT_DATA=
      (SERVER=dedicated)
      (SERVICE_NAME=<service_name>)
      (UR=A)
    )
  )