ORA-12154: TNS could not resolve service name specified
Sometimes you will see the error message related to tns.
Error message will be like this.
ORA-12154: TNS could not resolve service name specified
Solutions
- Check if your listener is up and running
- Check if listener is listening to database services.
- Look for tnsnames.ora file. database entry needs to be available there
- Syntax error in tnsnames.ora
- Service name might have an alias, so check for global entries and local entries
Location of tnsnames.ora and listener.ora will be as $ORACLE_HOME/network/admin/