Hi Lax -
Which Tableau Version are you using? Tableau provides native connection set up for Teradata DB. You simply have to provide server details and credentials in order to set up connectivity, assuming ports are open for DB connection in your environment.
Regarding large data : This has broader scope for discussion but best practice to handle data is provide highly aggregated view with less or no joins at Tableau end. You can define aggregated views and its granularity based on Visualization view that your planning to build.
=======>> Pl note "VIZ Talk" section is very specific to discuss visualization. In future you can post non-visualization related questions at Forums Tableau forum. You will able to target correct audience for your question. <<==========
Good luck, Sameer.
do we know how the native connection works?
how tableau built it?