今天要把测试环境DB的数据更新成最新Production环境的数据，期间发生了一些问题：

1.首先从正式环境exp出想要用户的dmp档

2.drop掉测试环境底下相应用户

3.create测试环境底下相应用户

4.imp 正式环境导出的dmp档

5.在测试环境底下explain plan sql时报：ORA-00980: synonym translation is no longer valid

用以下语句查下失效的synonym

select 'drop '
       || decode (s.owner,
                  'PUBLIC', 'public synonym ',
                  'synonym ' || s.owner || '.')
       || s.synonym_name
       || ';' as "Dropping invalid synonyms:"
  from dba_synonyms s
 where table_owner not in ('SYSTEM', 'SYS') and db_link is null
   and not exists
          (select null
             from dba_objects o
            where s.table_owner = o.owner
              and s.table_name = o.object_name)

发现有个TOAD_PLAN_TABLE的synonym失效，应该是我在砍User的时候，没有把这个同义词相应的砍掉

解决：drop public synonym TOAD_PLAN_TABLE;

然后在测试环境下进行explain plan一切正常

搞定！！！！！！！！！！！