If you want to minimize the performance hit on your OBIEE system, you can extract the OBIEE data into Tableau using BI Connector, save it as a Tableau Data Extract (.tde), and use it for offline analysis, sharing and collaboration.
See the video on how to do this:
As you saw in the video, after you drag and drop a table into the join area, be sure to choose Extract in the radio button. When you click on Worksheet, Tableau will prompt you to save the Tableau Data Extract (.tde) file in your PC. Tableau will store the data in a compressed and optimized format in this file.
To relaunch this worksheet, just double-click on the .tde file.