Error Encountered in Cognos 8.3 with Oracle XE

Below is the error message that I encountered when trying to run a report in Cognos.

CNC-MON-0024 Monitor Service paging error: Listener refused the connection with the following error: ORA-12519, TNS:no appropriate service handler found The Connection descriptor used by the client was: localhost:1521:XE

I am not too sure what is the actual cause of this error but below is the way that I solved it.

Launch SQL Plus and issue the the command as below:

SQL> connect / as sysdba;
Connected.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 285212672 bytes
Fixed Size 1287016 bytes
Variable Size 96472216 bytes
Database Buffers 184549376 bytes
Redo Buffers 2904064 bytes
Database mounted.

SQL> alter system set job_queue_process=20;
System altered.

SQL> alter system set PROCESSES=100 scope=SPFILE;
System altered.

SQL> alter system set open_cursors=300 scope=both;
System altered.

SQL> alter database open;
Database altered.

SQL> alter system disable restricted session;
System altered.

Hope this may helps. :)