create database link test_link  connect to xx identified by xx  using ‘(DESCRIPTION =  (ADDRESS_LIST =      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.xx.xx.xx7)(PORT = 1521))      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.xx.xx.xx6)(PORT = 1521))      (FAILOVER = on)      (LOAD_BALANCE = on)    )  (CONNECT_DATA =http://www.mamicode.com/(SERVER = DEDICATED)(SERVICE_NAME = ora11g)))‘;




load_balance=on 负载平衡

可以加也可以不加