今天在进行测试环境导数据的时候，需要记性drop user操作。在执行drop user的时候，提示：ORA-01940: cannot drop a user that is currently connected
SQL> drop user ecity ;
drop user ecity
*
ERROR at line 1:
ORA-01940: cannot drop a user that is currently connected
问题很明显，有用户在连接，不允许drop掉该user。
select username,sid,serial#,paddr from v$session where username='ECITY';
USERNAME SID SERIAL# PADDR
------------------------------ ---------- -------------------------------------------------
ECITY 634 7 00000000C028D198
SQL> select PROGRAM from v$process where addr='00000000C028D198';
PROGRAM
----------------------------------------------------------------------------------------------------------
Oracle@oradb01 (DW00)
SQL>
SQL> alter system kill session '634,7';
System altered.
SQL>
SQL> select saddr,sid,serial#,paddr,username,status from v$session where username is not null;
SQL> drop user ecity CASCADE;
User dropped.
SQL>
问题解决，记得KILL进程前，先看看是啥进程，哪台机连过来的，能否KILL等等。测试环境还好，生产无小事。