Cause
ORA-12154 occurs when the transparent network substrate (TNS) cannot resolve the service name. Most often, the SERVICE_NAME or HOST is incorrect.
Resolution
First, try providing the full database name with the .WORLD extension in the Step 1 text box of the Oracle Connection dialog box.
If the full database name doesn't resolve the issue, check the information in the TNSNames.ora file, which is located in your %ORACLE_HOME%\network\admin\ folder.
An example of a TNSNames.ora file is shown here:
QAORCL10.world =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = MY_HOST_NAME)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = MY_SERVICE_NAME)
)
)
The three variables of interest in the file are HOST, PORT, and SERVICE_NAME. Copy these variables from the TNSNames.ora file and keep them available. Note that these variables are case sensitive.
To provide these variables for your connection:
Step 1
In the Tableau Data window, select Connect to Data.
Step 2
In the Connect to Data dialog box, select Oracle, and then click Next.
Step 3
In the Oracle Connection dialog box, click Advanced.
Step 4
In the Advanced Oracle Connection dialog box, in the Server Name text box, provide the HOST name from the TNSNames.ora file. Remember that the variables are case sensitive.
Step 5
In the Service Name text box, provide the SERVICE_NAME from the TNSNames.ora file, and in the Port box, provide the PORT number.
Step 6
When finished, click OK.
Step 7
In the Oracle Connection dialog box, under Step 2, provide the Username and Password.
Step 8
Under Step 3, click Test Connection.
Step 9
When a message box opens to notify you that the connection was successful, click OK.
Step 10
Under Step 4, select a schema from the list.
Step 11
Under Step 5, keep the selection of Single Table, and select a table or view from the schema.
Step 12
Under Step 6, you have the option to edit the default connection name.
Step 13
When finished, click OK.
