oracle:/home/oracle>sqlplus /nolog
SQL*Plus: Release 12.1.0.2.0 Production on Tue May 31 08:58:49 2016
Copyright (c) 1982, 2014, Oracle. All rights reserved.
SQL> connect / as sysdba
Connected to an idle instance.
SQL> startup mount exclusive restrict
ORACLE instance started.
Total System Global Area 1275068416 bytes
Fixed Size 2946064 bytes
Variable Size 973081584 bytes
Database Buffers 285212672 bytes
Redo Buffers 13828096 bytes
Database mounted.
SQL> drop database ;
Database dropped.
Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL> connect / as sysdba
Connected to an idle instance.