1) Disable the Constrains:

SQL> select 'ALTER TABLE '||owner||'.'||table_name||' DISABLE CONSTRAINT '|| constraint_name||';'
from dba_constraints
where (index_owner,index_name) in (select owner,index_name from dba_indexes
where tablespace_name='MY_TBS');

2) In case of PKs, you may need to disable it with CASCADE clause:

SQL> select 'ALTER TABLE '||owner||'.'||table_name||' DISABLE CONSTRAINT '|| constraint_name||' cascade;'
from dba_constraints
where (index_owner,index_name) in (select owner,index_name from dba_indexes
where tablespace_name='MY_TBS');

3) Drop the tablespace:

SQL> DROP TABLESPACE MY_TBS INCLUDING CONTENTS AND DATAFILES;

补充一下，既然是分别处理U和P，那么第一二句可合并成以下：

select 'ALTER TABLE '||owner||'.'||table_name||' DISABLE CONSTRAINT '|| constraint_name||decode(constraint_type ,'P',' CASCADE','')||';'
from dba_constraints where constraint_type in ('U','P') and (index_owner,index_name) in
(select owner,index_name from dba_indexes where tablespace_name='INDX');

还有一个问题，执行了这个sql后，DROP TABLESPACE MY_TBS INCLUDING CONTENTS AND DATAFILES;发现磁盘空间大小还是没变，我新建了一个表空间在data1上面，发现表空间使用率还是和原来一样

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用lsof | gerp deleted发现删除的文件没有释放，最后用kill pid，磁盘文件释放了