Oracle Database Errors or Warnings from Error ORA-12523 to ORA-12532
ORA-12523: TNS:listener could not find instance appropriate for the client connection
Cause: The listener could not find any available (database) instances, that are appropriate for the client connection.
Action: Run “lsnrctl services” to ensure that the instance(s) are registered with the listener, and have status READY.
ORA-12524: TNS:listener could not resolve HANDLER_NAME given in connect descriptor
Cause: The HANDLER_NAME in the CONNECT_DATA was not found in the listener’s tables for the specified SERVICE_NAME and INSTANCE_NAME.
Action: Check to make sure that the HANDLER_NAME specified is correct.
ORA-12525: TNS:listener has not received client’s request in time allowed
Cause: The listener disconnected the client because the client failed to provide the necessary connect information within the allowed time interval. This may be a result of network or system delays; or this may indicate that a malicious client is trying to cause a Denial of Service attack on the listener.
Action: If the error occurred because of a slow network or system, reconfigure INBOUND_CONNECT_TIMEOUT to a larger value. If a malicious client is suspected, use the address in listener.log to identify the source and restrict access. Turn on tracing for more information.
ORA-12526: TNS:listener: all appropriate instances are in restricted mode
Cause: Database instances supporting the service requested by the client were in restricted mode. The Listener does not allow connections to instances in restricted mode. This condition may be temporary, such as during periods when database administration is performed.
Action: Attempt the connection again. If error persists, then contact the database administrator to change the mode of the instance, if appropriate.
ORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections
Cause: All appropriate database instances supporting the service requested by the client reported that they either were in restricted mode or were blocking the new connections. The Listener does not allow connections to such instances. This condition may be temporary, such as at instance startup.
Action: Attempt the connection again. If error persists, then contact the database administrator to check the status of the instances.
ORA-12528: TNS:listener: all appropriate instances are blocking new connections
Cause: All instances supporting the service requested by the client reported that they were blocking the new connections. This condition may be temporary, such as at instance startup.
Action: Attempt the connection again. If error persists, then contact the administrator to check the status of the instances.
ORA-12529: TNS:connect request rejected based on current filtering rules
Cause: Connection Manager and its listener were configured with filtering rules specifying that the connect request be rejected.
Action: If this connect request should be allowed, then contact the administrator to modify the filtering rules.
ORA-12531: TNS:cannot allocate memory
Cause: Sufficient memory could not be allocated to perform the desired activity.
Action: Either free some resource for TNS, or add more memory to the machine. For further details, turn on tracing and reexecute the operation.
ORA-12532: TNS:invalid argument
Cause: An internal function received an invalid parameter.
Action: Not normally visible to the user. For further details, turn on tracing and reexecute the operation. If error persists, contact Oracle Customer Support.
Above are list of Oracle Database Errors or Warnings from Error ORA-12523 to ORA-12532 received while performing certain operation against Oracle Database or related products.
What are Oracle Database Error Messages?
Oracle Error Messages may be returned while using products which are part of Oracle Database. Each Oracle Database Error or Warning Message mentioned above contains the Warning or Error Message Statement, a short explanation of the probable causes of the Error message, and a recommended action.
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Information about Oracle Database Error Messages or Warning Messages on Windows and Linux Operating Systems.