Review database connection issues.

The following are the common Oracle Database connection error codes, their causes, and suggested remedies.

TNS-12203

TNS: unable to connect to destination

Cause: OracleServiceSID service, OracleHOMENAMETNSListener service, or both are not running.

Action: Ensure that both services are started.

ORA-12560

TNS: lost contact

Cause: OracleServiceSID service, OracleHOMENAMETNSListener service, or both are not running. You receive this error if you attempt to use any Oracle Database utilities, such as SQL*Plus. This error is analogous to the following Oracle7 error: ORA-09352: Windows 32-bit Two-Task driver unable to spawn new ORACLE task.

Action: Ensure that both services are started.

ORA-28575

unable to open RPC connection to external procedure agent

Cause: tnsnames.ora and listener.ora files have not been correctly configured to use external procedures.

Action: Reconfigure services.

ORA-06512

at "APPLICATIONS.OSEXEC", line 0

Cause: tnsnames.ora and listener.ora files have not been correctly configured to use external procedures.

Action: Reconfigure services.

ORA-06512

at "APPLICATIONS.TEST", line 4

Cause: tnsnames.ora and listener.ora files have not been correctly configured to use external procedures.

Action: Reconfigure services.

ORA-06512

at line 2

Cause: tnsnames.ora and listener.ora files have not been correctly configured to use external procedures.

Action: Reconfigure services.

ORA-01031 and LCC-00161

Both codes appear at startup

Cause: Parameter file (init.ora) or Windows services are damaged. These errors usually appear when the parameter file cannot be read by Oracle Database at database startup.

Action: Delete and re-create the SID and services. Make sure you are logged on as the user Administrator, or a user within the Windows Administrator's Group with full administrative rights. At the command prompt, enter: oradim -delete -sid sid where sid is the name of your database (for example, orcl). Re-create the SID and services by entering: oradim -new -sid sid -startmode auto -pfile full_path_to_init.ora