Cancel Oracle shutdown
You might want to cancel a shutdown if you issued the wrong command when there were connected users.
If you try to shutdown immediate from another session, you’ll get this:
SQL> shutdown IMMEDIATE ORA-24324: service handle NOT initialized ORA-24323: VALUE NOT allowed ORA-01089: IMMEDIATE shutdown IN progress - no operations are permitted
When you issue a shutdown, only the SYS/SYSTEM user will be able to connect, so open another SQL*Plus session and type this:
CONNECT /AS sysdba startup force