cd $ORACLE_HOME/network/admin

vi tnsnames.ora

添加

CCPBS_19 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 10.130.38.19)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = CCPBS)
    )
  )

>create public database link ecbm_19 connect to ecbm_userName identified by ecbm_pwd using 'CCPBS_19';

Database link created.

createpublicdatabaselink link_name connectto user identifiedby password using 'SID';

则创建了一个连接到10.130.38.19 ccpbs上以ecbm_userName 用户的连接

查询数据时带上@ecbm_19 就ok了 如select * from emp@ecbm_19;

删除 DROPPUBLICDATABASELINK ecbm_19;

　3、建立同义词，为了使有关分布式操作更透明，ORACLE数据库里有同义词的对象synonym　

　　SQL>create synonym bjscottemp for emp@beijing;

　　于是就可以用bjscottemp来替代带@符号的分布式链接操作emp@beijing。

create public synonym poh for po_headers_all@erp_danzheng_test;

查看所有的数据库链接，进入系统管理员SQL>操作符下，运行命令：

SQL>select owner,object_name from dba_objects where object_type='DATABASE LINK';