drop tablespace 的同时 查看v$trxwait 看看什么阻塞这个动作

看着可能是还有语句在占用表空间上的一些对象，查下有没有阻塞，把引起阻塞的会话关闭后再试试，也就是FM_SESS_ID对应的会话

SELECT SYSDATE STATTIME,DATEDIFF(SS,S1.LAST_SEND_TIME,SYSDATE) SS,
'被阻塞的信息' WT,S1.SESS_ID WT_SESS_ID,S1.SQL_TEXT WT_SQL_TEXT,S1.STATE WT_STATE,S1.TRX_ID WT_TRX_ID,
S1.USER_NAME WT_USER_NAME,S1.CLNT_IP WT_CLNT_IP,S1.APPNAME WT_APPNAME,S1.LAST_SEND_TIME WT_LAST_SEND_TIME,
'引起阻塞的信息' FM,S2.SESS_ID FM_SESS_ID,S2.SQL_TEXT FM_SQL_TEXT,S2.STATE FM_STATE,S2.TRX_ID FM_TRX_ID,
S2.USER_NAME FM_USER_NAME,S2.CLNT_IP FM_CLNT_IP,S2.APPNAME FM_APPNAME,S2.LAST_SEND_TIME FM_LAST_SEND_TIME
FROM V$SESSIONS S1,V$SESSIONS S2,V$TRXWAIT W
WHERE S1.TRX_ID=W.ID
AND S2.TRX_ID=W.WAIT_FOR_ID;