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I am trying to shutdown the system, then I want to mount it. I have tried this:

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
SQL> startup mount;
ORA-24324: service handle not initialized
ORA-01041: internal error. hostdef extension doesn't exist

I have googled for solution but I can't found the exact reason that causes it to go wrong.

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I don't suppose a reboot fixes this? – kevinsky Jul 10 '12 at 13:40

Exit sqlplus.

Make sure your os user is part of the DBA group (ORA_DBA in Windows).

Make sure ORACLE_SID is set to the SID of the database and unset TWO_TASK:





export TWO_TASK

Now, connect as sysdba:

sqlplus / as sysdba

Now, startup the database:

SQL> startup mount;

SQL> alter database open;
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set ORACLE_SID=database


sqlplus /nolog

CONNECT /@database as sysdba


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You should describe why this works. – Max Vernon Nov 7 '13 at 12:30

Once you have closed the database, you need to reconnect

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How can i reconnect. when database is shutdown. – madhu Jul 11 '12 at 5:30
@madhu I think steve meant, close sqlplus and relaunch. – Leigh Riffel Jul 11 '12 at 12:47
Wait, why is the TNS listener involved in this? Is this being done on a remote machine? Do it from the actual box that Oracle is running on. – Gaius Jul 11 '12 at 14:21
@Gaius I am running under the same machine where oracle is installed – madhu Jul 12 '12 at 5:13
@Leigh Riffel please help me(Steps required) how to connect to sqlplus. after the oracle instance is shutdown. – madhu Jul 12 '12 at 5:15

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