同义词的所有者跟目标数据库对象的所有者通常是不一样的，也可以一样。当所有者不一样的时候，需要确保同义词的所有者有权限访问实际对象所有者对应的表。

    CREATE SYNONYM 语句用来创建同义词，语法格式如下：

    1. CREATE SYNONYM synonym_name FOR [owner.]object_name ;

    示例：创建跨数据库所有者的同义词

    创建单独的用户 tpcc_ro ，对用户 tpcc 赋权允许使用 grant 命令。

    1. obclient> create user tpcc_ro identified by 123456;
    2. Query OK, 0 rows affected (0.04 sec)
    4. obclient> grant all privileges on tpcc_ro.* to tpcc_ro;
    5. Query OK, 0 rows affected (0.02 sec)
    7. obclient> grant create synonym on *.* to tpcc_ro ;
    8. Query OK, 0 rows affected (0.02 sec)
    10. obclient> grant select on sys.* to tpcc_ro ;
    11. Query OK, 0 rows affected (0.01 sec)
    13. obclient> grant all privileges on tpcc.* to tpcc with grant option;
    14. Query OK, 0 rows affected (0.02 sec)

    登录 tpcc 用户，授权用户 tpcc_ro 读取表 ordr 、ordl。

    1. $obclient -h127.1 -utpcc@oracle0_85#obv22_stable -P2883 -p123456 tpcc
    3. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
    5. obclient> grant select on ordr to tpcc_ro;
    6. Query OK, 0 rows affected (0.02 sec)
    8. obclient> grant select on ordl to tpcc_ro;
    9. Query OK, 0 rows affected (0.01 sec)

    登录 tpcc_ro 用户，创建同义词。

    1. obclient> create synonym ordr for tpcc.ordr;
    2. Query OK, 0 rows affected (0.02 sec)
    4. obclient> create synonym ordl for tpcc.ordl;
    5. Query OK, 0 rows affected (0.01 sec)
    7. obclient> select count(*) from ordr t1 join ordl t2 on (t1.o_w_id=t2.ol_w_id and t1.o_d_id=t2.ol_d_id and t1.o_id=t2.ol_o_id);
    8. +----------+
    9. | COUNT(*) |
    10. +----------+
    11. |      626   |
    12. +----------+
    13. 1 row in set (0.02 sec)
    15. obclient> select * from user_synonyms;
    16. +--------------+-------------+------------+---------+
    17. | SYNONYM_NAME | TABLE_OWNER | TABLE_NAME | DB_LINK |
    18. +--------------+-------------+------------+---------+
    19. | ORDR           | TPCC         | ORDR         | NULL     |
    20. | ORDL           | TPCC         | ORDL         | NULL     |
    21. | WARE           | TPCC         | WARE         | NULL     |
    22. +--------------+-------------+------------+---------+
    23. 3 rows in set (0.02 sec)