TNS Listener Error Messages (ORA-12500 to 12530)

Cause:	The process of starting up a dedicated server process failed. The executable could not be found or the environment may be set up incorrectly.

Action:	Turn on tracing at the ADMIN level and reexecute the operation. Verify that the ORACLE Server executable is present and has execute permissions enabled. Ensure that the ORACLE environment is specified correctly in LISTENER.ORA. If error persists, contact Worldwide Customer Support.

ORA-12502 TNS:listener received no CONNECT_DATA from client

Cause:	No CONNECT_DATA was passed to the listener.

Action:	Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor.

ORA-12504 TNS:listener was not given the SID in CONNECT_DATA

Cause:	The SID was missing from the CONNECT_DATA.

Action:	Check that the connect descriptor corresponding to the service name in TNSNAMES.ORA has an SID component in the CONNECT_DATA.

ORA-12505 TNS:Listener could not resolve SID given in connect descriptor

Cause:	The SID in the CONNECT_DATA was not found in the listener's tables.

Action:	Check to make sure that the SID specified is correct. The SIDs that are supported can be obtained by typing LSNRCTL STATUS SERVICE_NAME and matching the SID specified in TNSNAMES.ORA with one of the SIDs displayed in the services summary.

ORA-12509 TNS:listener failed to redirect client to service handler

Cause:	The dispatcher terminated unexpectedly.

Action:	Attempt to connect again and if the same error occurs, contact the DBA to check the state of the dispatchers for this SID. If the problem persists, turn on tracing in the listener to determine the TNS error caused by the redirect.

ORA-12510 TNS:database lacks resources to handle the request for this SID

Cause:	The dispatchers are busy handling other requests.

Action:	Contact the DBA to increase the number of dispatchers servicing this SID.

ORA-12511 TNS:service handler found but it is not accepting connections

Cause:	The dispatchers are busy handling other requests and they notified the listener that they were temporarily busy.

Action:	Attempt the connection again. If the error persists, ask the DBA to increase the number of dispatchers.

ORA-12512 TNS:service handler found but it has not registered a redirect address

Cause:	The dispatcher just came up and has not had time yet to register the address that a client should be redirected to.

Action:	Attempt the connection again. If the error persists, ask the DBA to increase the number of dispatchers.

ORA-12513 TNS:service handler found but it has registered on a different protocol

Cause:	The dispatchers registered for this service are connected to the listener by way of a different network protocol than that of the client.

Action:	Contact the DBA to register a dispatcher on your protocol.