Oracle 10g - Drop database

Following tests show that drop database works in 10g, but not in 9i

tx2qdfsdb1:TOY10G: /ora01/orabkup/MYDBQ/.temp_toy10g/oracle/admin/TOY10G > sqlplus / as sysdba
SQL*Plus: Release 10.2.0.3.0 - Production on Sat Sep 8 15:32:24 2007
Copyright (c) 1982, 2006, Oracle. All Rights Reserved.
Connected to:

Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production

With the Partitioning, OLAP and Data Mining options

sys@TOY10G> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

sys@TOY10G> startup mount;

ORACLE instance started.

Total System Global Area 268435456 bytes
Fixed Size 2029392 bytes
Variable Size 167774384 bytes
Database Buffers 92274688 bytes
Redo Buffers 6356992 bytes
Database mounted.
sys@TOY10G> drop database;
drop database
*

ERROR at line 1:

ORA-12719: operation requires database is in RESTRICTED mode


sys@TOY10G> alter system enable restricted session;

System altered.

sys@TOY10G> drop database;

ERROR:

ORA-01034: ORACLE not available

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
------------------

tx2qdfsdb1:TOY9I: /ora01/orabkup/MYDBQ/.temp_toy10g/ora01/oradata/TOY9I > sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - Production on Sat Sep 8 15:38:42 2007

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

idle> conn / as sysdba

Connected to an idle instance.

idle> startup mount;

ORACLE instance started.

Total System Global Area 589269776 bytes
Fixed Size 731920 bytes
Variable Size 553648128 bytes
Database Buffers 33554432 bytes
Redo Buffers 1335296 bytes
Database mounted.
idle> drop database
2 ;

*

ERROR at line 2:
ORA-02026: missing LINK keyword