Cannot connect to Oracle 10g database

From SQL PLus, I cannot connect to our Oracle 10g database. The following errors shows up in the SQL-Plus.

ORA-12514: TNS:listener does not currently know of service requested in connect
descriptor

The same error comes even after a day, the database had been started.

Database start fine without any errors, when it is started from Services. The emoms.log shows the following errors.

2008-04-22 17:28:20,234 [HttpRequestHandler-24044524] ERROR conn.ConnectionService verifyRepositoryEx.434 - Invalid Connection Pool. ERROR = Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
The Connection descriptor used by the client was:
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=supportdb
3.actuate.com)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl10g)))

2008-04-22 17:28:20,250 [HttpRequestHandler-24044524] ERROR eml.OMSHandshake getParameterFromDB.563 - Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
The Connection descriptor used by the client was:
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=supportdb
3.actuate.com)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl10g)))

2008-04-22 17:28:20,250 [HttpRequestHandler-24044524] ERROR eml.OMSHandshake processFailure.780 - OMSHandshake failed.(AGENT URL = http://support-db3.actuate.com:3938/emd/main)(ERROR = INTERNAL_ERROR) 2008-04-22 17:28:20,312 [HttpRequestHandler-20677779] ERROR conn.ConnectionService verifyRepositoryEx.434 - Invalid Connection Pool. ERROR = Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
The Connection descriptor used by the client was:
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=supportdb
3.actuate.com)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl10g)))

2008-04-22 17:28:20,328 [HttpRequestHandler-20677779] ERROR eml.OMSHandshake getParameterFromDB.563 - Listener refused the connection with the following error:
ORA-12514, TNS:listener does not currently know of service requested in connect descriptor
The Connection descriptor used by the client was:
(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=supportdb
3.actuate.com)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl10g)))

2008-04-22 17:28:20,328 [HttpRequestHandler-20677779] ERROR eml.OMSHandshake processFailure.780 - OMSHandshake failed.(AGENT URL = http://support-db3.actuate.com:3938/emd/main)(ERROR = INTERNAL_ERROR)

What could be the problem and how to fix it?

Any help you can provide is greatly appreciated.

Thank you.
Raj Received on Tue Apr 22 2008 - 19:30:44 CDT