补充:http://space.itpub.net/267265/viewspace-713311

1.建立测试表空间以及测试表.
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

SQL> CREATE TABLESPACE testx DATAFILE
   SIZE 10M AUTOEXTEND ON NEXT 1M MAXSIZE UNLIMITED
LOGGING
PERMANENT
EXTENT MANAGEMENT LOCAL AUTOALLOCATE
BLOCKSIZE 8K
SEGMENT SPACE MANAGEMENT AUTO
FLASHBACK ON;

SQL> create table t(id number) tablespace testx;

SQL> select * from user_segments where SEGMENT_NAME='T';

no rows selected

2.由于不占用空间,删除表空间没有问题.
drop tablespace testx;

3. 执行如下:
SQL> select * from t;
select * from t
              *
ERROR at line 1:
ORA-00959: tablespace 'TESTX' does not exist
--如果在删除表空间前执行以上语句,可以执行(因为语句已经已经分析过,在共享池中),要修改一下:
Select * from t;
--这样就会报ora-00959错误.

SQL> drop table t  ;
drop table t
           *
ERROR at line 1:
ORA-00959: tablespace 'TESTX' does not exist

SQL> drop table t purge ;
Table dropped.

还好drop table+purge可以删除.