Connecting Tableau Desktop to Vertica
For optimal performance and functionality, Hewlett Packard Enterprise recommends that you connect to Vertica from Tableau using Tableau's Vertica native connector.
To connect to Vertica using the native connector, follow these steps:
1. Launch Tableau Desktop.
The Connect page opens.
2. On the Connect page, under To a server, select More Servers > HP Vertica.
3. On the Server Connection page, enter the server name, database name, username, and password.
4. Click OK to make the connection.
5. From the Schema drop-down list, select or search for the schema you want to work with.
After you select a schema, a list of tables in that schema appears.
6. To define a data source for your visualizations, do one of the following:
• Drag and drop tables to the join area. Tableau tries to guess the joins between the tables.
• Click New Custom SQL to enter a query that returns data that you use to design your dashboards.
7. After you define your data source, click Sheet1 to start designing your visualizations.
Source : https://intellipaat.com/tutorial/tableau-tutorial/