1.USER_A的数据保存在多个表空间中，首先导出USER_A的数据：
exp USER_A/PASS_A@DB_A file=USER_A_BAK.dmp log=exp_USER_A.log
2.创建用户USER_B:
create user USER_B
identified by "USER_B"
default tablespace USER_B_DEFAULT_TABLESPACE
temporary tablespace TEMP
profile DEFAULT
quota unlimited on USER_B_DEFAULT_TABLESPACE;
grant connect to USER_B with admin option;
--grant dba to USER_B with admin option;
--grant resource to USER_B;
grant create any table to USER_B with admin option;
grant delete any table to USER_B with admin option;
grant insert any table to USER_B with admin option;
grant select any table to USER_B with admin option;
--grant unlimited tablespace to USER_B with admin option;
grant update any table to USER_B with admin option;
3.导入数据到USER_B:
imp USER_B/USER_B@DB_B file=USER_A_BAK.dmp fromuser=USER_A touser=USER_B log=imp_USER_B.log
4.注意点：
--前面不能授予这些权限(在第二步已经注释)，导完后授权
grant dba to USER_B with admin option;
grant resource to USER_B;
grant unlimited tablespace to USER_B with admin option;
