Connecting Tableau to Rational Data Warehouse
One answer
George, I've never used Tableau Desktop, but I have used Python and Jypyter notebooks to explore ELM data from various data sources including OSLC REST HTTP methods, Reportable REST API, RTC SCM Command Line Interface (using JSON), LQE SPARQL queries, and executing RTC stored queries and processing the XML results. I have not used the DWH, but I'm sure that's possible too.
I don't know of any reusable data blocks that do this, but it shouldn't be too hard to create them. It will require authentication and login, and typically making REST calls and processing the results to get them into a consumable format. I used pandas DataFrames for analysis for example.