You don't need to republish but you might need to reboot the computer running Tableau Server after installing the proper database drivers. Check out our new drivers page! Drivers & Activation | Tableau Software
i installed hadoop driver and restarted the server. but getting the below issue when testing the connection
Could not connect to server
The drivers necessary to connect to the database server '10.18.31.29' are not properly installed on Tableau Server. Visit http://www.tableau.com/drivers to download driver setup files.
[Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified