create database link DBLINK_IMARK_RAC

  connect to imark identified by  imarkDB12345

  using '(DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.7.114)(PORT = 1521))

    (ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.7.116)(PORT = 1521))

    (LOAD_BALANCE = yes)

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SERVICE_NAME = center)

      (FAILOVER_MODE =

        (TYPE = SELECT)

        (METHOD = BASIC)

        (RETRIES = 180)

        (DELAY = 5)

      )

    )