ORA-12154 TNS:could not resolve the connect identifier specified
This is an Oracle Database Server Message. This can be generated by the Oracle Database when running any Oracle program.
What is the cause of ORA-12154 from Oracle 11g ?
How to deal with ORA-12154 from Oracle 11g ?
This is in general the very first error message you get when you try to establish a connection to your oracle database. Often, it's a typographical error in your connexion string or in your tnsnames.ora file.
If you are using local naming (TNSNAMES.ORA file):
- Make sure that "TNSNAMES" is listed as one of the values of the NAMES.DIRECTORY_PATH parameter in the Oracle Net profile (SQLNET.ORA)
- Verify that a TNSNAMES.ORA file exists and is in the proper directory and is accessible (general tnsnames.ora location is: $ORACLE_HOME/network/admin/tnsnames.ora).
- Check that the net service name used as the connect identifier exists in the TNSNAMES.ORA file.
- Make sure there are no syntax errors anywhere in the TNSNAMES.ORA file. Look for unmatched parentheses or stray characters. Errors in a TNSNAMES.ORA file may make it unusable.
If you are using directory naming:
- Verify that "LDAP" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
- Verify that the LDAP directory server is up and that it is accessible.
- Verify that the net service name or database name used as the connect identifier is configured in the directory.
- Verify that the default context being used is correct by specifying a fully qualified net service name or a full LDAP DN as the connect identifier
If you are using easy connect naming:
- Verify that "EZCONNECT" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
- Make sure the host, port and service name specified are correct.
- Try enclosing the connect identifier in quote marks. See the Oracle Net Services Administrators Guide or the Oracle operating system specific guide for more information on naming.
Contacting Oracle support services ?
Some messages recommend contacting Oracle Support Services to report a problem. Please go here for more information : Oracle Support.
Linked Error Messages
- ORA-12150 TNS:unable to send data
- ORA-12151 TNS:received bad packet type from network layer
- ORA-12152 TNS:unable to send break message
- ORA-12153 TNS:not connected
- ORA-12155 TNS:received bad datatype in NSWMARKER packet
- ORA-12156 TNS:tried to reset line from incorrect state
- ORA-12157 TNS:internal network communication error
- ORA-12158 TNS:could not initialize parameter subsystem
- ORA-12159 TNS:trace file not writeable
- ORA-12160 TNS:internal error: Bad error number
- ORA-12161 TNS:internal error: partial data received
- ORA-12162 TNS:net service name is incorrectly specified