In your case, if I have added Initial SQL in Tableau, then I would ensure to input the correct SQL command in the Initial SQL for successful sign in to the Denodo database. This command will be executed whenever Tableau establishes a connection with Denodo using the provided user login.
In case if the connection succeeded and you are able to sign in to the Database, but you are not able to see the base views, then you could check if the user has required privileges to connect to the base views. To analyze more on your behavior, you could check the **vdp.log** file located in the path ***<DENODO_HOME>/logs/vdp/***.
If required, you could also enable log level for **vdp-queries** and **vdp-requests** by following the articles [Configuring the Logging Engine](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/appendix/configuring_the_logging_engine/configuring_the_logging_engine#configuring-the-logging-engine) and [How to log the requests issued on a VDP server](https://community.denodo.com/kb/view/document/How%20to%20log%20the%20requests%20issued%20on%20a%20VDP%20server?category=Operation) to troubleshoot in detail.
For more information, you could refer to the Knowledge Base article [How to connect to Denodo from Tableau Desktop](https://community.denodo.com/kb/view/document/How%20to%20connect%20to%20Denodo%20from%20Tableau%20Desktop?category=Northbound+Connections) on configuration steps.
Hope this helps!