Oracle中建立了dblink怎么使用

SELECT * FROM GLOBAL_NAME;

show parameter global_name

CREATE DATABASE LINK数据库链接名

     CONNECT TO 用户名

     IDENTIFIED BY 密码

     USING ‘数据库连接字符串';

CREATE PUBLIC DATABASE LINK CONN_MY_LINK

    CONNECT TO MYUSER IDENTIFIED BY MYPASSWORD

    USING 'MYORAL' ;

CREATE PUBLIC DATABASE LINK LINK_HSMIS

       CONNECT TO BI

       IDENTIFIED BY BI

      USING '(DESCRIPTION =

            (ADDRESS_LIST =

            (ADDRESS = (PROTOCOL = TCP)(HOST = 10.188.245.201)(PORT = 1521))

            )

           (CONNECT_DATA =

           (SERVICE_NAME = hsmis)

           )

       )' ;

// 赋予创建权限

     grant CREATE DATABASE LINK to smis;   

     grant CREATE SYNONYM to smis;

SELECT * FROM DUAL@数据库链接名

   或 SELECT * FROM 表名@数据库链接名

drop public database link CONN_MY_LINK

CREATE SYNONYM S_MY_TABLE FOR TABLENAME@数据库链接名;

A_TO_B = 

    (DESCRIPTION = 

    (ADDRESS_LIST = 

    (ADDRESS = (PROTOCOL = TCP)(HOST =A2服务器的IP)(PORT = 1521)) )    

    (CONNECT_DATA = 

    (SERVICE_NAME = B数据库的服务名)))

select sess.sid, 

   sess.serial#, 

   lo.oracle_username, 

   lo.os_user_name, 

   ao.object_name, 

   lo.locked_mode 

   from v$locked_object lo, 

   dba_objects ao, 

   v$session sess 

   where ao.object_id = lo.object_id and lo.session_id = sess.sid;

select * from v$session t1, v$locked_object t2

   where t1.sid = t2.SESSION_ID;

alter system kill session 'SID,serial' ;