Expert Oracle Database Tips by Donald Burleson August 27, 2015
Question: I am attempting to enter SQL*Plus and I am getting this error:
oracle> sqlplus system/manager@mysid
ORA-12514: TNS: Listener does not currently know of service requested in connect descriptor
How do I prevent this form of the ORA-12514 error? Also, I often get a TNS-12514 along with the ORA-12514. Are these the same error? If not, how do I avoid the TNS-12514?
Answer: First, the ORA error is a permutation of the ORA-12514: TNS listener cannot resolve service name error as shown below. This form of the ORA-12541 error commonly happens when the database or the listener processes are in the middle of a startup, or when the database (mysid in your case) has not been registered with the listener.
root> oerr ora 12514
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor
The listener received a request to establish a connection to a database or other service.
The connect descriptor received by the listener specified a service name for a service (usually a database service) that either has not yet dynamically registered with the listener or has not been statically configured for the listener.
This may be a temporary condition such as after the listener has started, but before the database instance has registered with the listener.
Wait a moment and try to connect a second time.
Check which services are currently known by the listener by executing: lsnrctl services
Check that the SERVICE_NAME parameter in the connect descriptor of the net service name used specifies a service known by the listener.
If an easy connect naming connect identifier was used, check that the service name specified is a service known by the listener.
Check for an event in the listener.log file.
To register the database with the listener
You have two options to register your database with the listener:
The TNS-12514 is very similar to the ORA-12514 for a reason. Sometimes Oracle does not get far enough along in the process for an Oracle error, so a similar network error will appear. Resolving one should take care of the other.
Read on for specific information on dealing with the TNS-12514 on Windows.
ORA-12514: TNS listener cannot resolve service name error
Question: I have an issue causing a ORA-12514: TNS: listener could not resolve SERVICE_NAME error:
SQL> shutdown immediate
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.
ORA-12514: TNS:listener could not resolve SERVICE_NAME given in connect descriptor
I’m using Oracle 10g on Windows 2000.
What’s cause of this error and how to resolve it?
Answer by Edward Stoever:
I avoid using a listener connection when I startup or shutdown, as a matter of practice. I realize that cannot always be done. Are you physically on the machine? Can you ssh or telnet in and run sqlplus on the box? Then connect like so:
export ORACLE_S >sqlplus sys as sysdba
[no password needed – just hit return ]
SQL> startup mount
Do not connect with the @mydb to avoid the listener.
Also, Windows systems are subject to a variety of other issues from screen savers that hog the CPU to the Catch-22 of either anti-virus protection or a virus interfering with connections. These conditions and a few others can cause TNS-12514 to appear.
Also note the similarities in numbering and content for ORA-12154, which deals with TNS inability to resolve the service name.
Burleson is the American Team
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