在10g以前，要彻底删除数据库，只有两个方法，一个是利用DBCA图形化工具删除数据库，另外一个就是关闭数据库后，手工删除数据文件、控制文件以及日志文件的方法。

从10g开始，Oracle提供了DROP DATABASE的语法，使得数据库的删除变得非常的简单。





不过DROP DATABASE还是有一定的限制条件的：

SQL> conn / as sysdba
Connected.
SQL> drop database;
drop database
*
ERROR at line 1:
ORA-01586: database must be mounted EXCLUSIVE and not open for this operation


SQL> alter database close;

Database altered.

SQL> drop database;
drop database
*
ERROR at line 1:
ORA-12719: operation requires database is in RESTRICTED mode


SQL> alter system enable restricted session;

System altered.

SQL> drop database;

Database dropped.

Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
SQL> exit
[oracle@bjtest ~]$ ps -ef|grep test102
oracle 15805 14913 0 06:13 pts/1 00:00:00 grep test102

数据库必须处于MOUNT状态，且设置了RESTRICTED SESSION。执行了DROP DATABASE命令后，Oracle自动删除控制文件，已经控制文件中记录的数据文件和在线重做日志文件，如果数据库使用了SPFILE，那么SPFILE文件也会删除。这个命令不会删除归档文件和备份文件。

在alert文件中，可以看到drop database对应的操作：

drop database
Mon May 18 06:13:01 2009
Deleted file /data/oradata/test102/system01.dbf
Deleted file /data/oradata/test102/undotbs1.dbf
Deleted file /data/oradata/test102/sysaux01.dbf
Deleted file /data/oradata/test102/redo01.log
Deleted file /data/oradata/test102/redo02.log
Deleted file /data/oradata/test102/redo03.log
Deleted file /data/oradata/test102/redo04.log
Deleted file /data/oradata/test102/redo05.log
Deleted file /data/oradata/test102/redo06.log
Deleted file /data/oradata/test102/redo07.log
Deleted file /data/oradata/test102/temp01.dbf
Instance terminated by USER, pid = 15795
Deleted file /data/oradata/test102/control01.ctl
Completed: drop database
Mon May 18 06:13:08 2009
Shutting down instance (abort)
License high water mark = 1