oracle database link 工作记录
SQL> conn /as sysdba
Connected.
SQL> grant CREATE DATABASE LINK to doudou;
Grant succeeded.

SQL> conn doudou/doudou2013
Connected.
SQL> create database link doudou_133 connect to xiaoyu identified by xiaoyu2010 using 'doudou_133';
Database link created.

oracle database link 学习
http://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_5005.htm#SQLRF01205
http://docs.oracle.com/cd/B19306_01/server.102/b14231/ds_admin.htm#i1007986

1、权限
private database link : CREATE DATABASE LINK system privilege.
public database link : CREATE PUBLIC DATABASE LINK system privilege.
remote oracle database: CREATE SESSION system privilege on the remote oracle database.
2、tnsnames.ora配置
DOUDOU =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.10)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = doudou)
    )
  )
3、创建database link语法
private database link : create database link link_pv_doudou connect to doudou identified by oracle using 'doudou';
public database link : create public database link link_pu_doudou connect to doudou identified by oracle using 'doudou';

4、database link视图 user_db_links、dba_db_links

5、删除database link语法
private database link : drop database link link_pv_doudou;
public database link : drop public database link link_pu_doudou;

6、拓展
本地用户会继承远程用户的权限，所以本地用户想添加权限，只需要添加远程的权限就可以了。