Understanding live connections and extracts – scenarios for using each

When you first connect to a data source in Tableau Desktop or via the Tableau web client, the default connection type is set to live. A live connection means that Tableau will use the query engine of the data source engine for every query from Tableau. This also means that the data in your Tableau workbooks will always be fresh or up to date with the information that is in the underlying data source.

The alternative to live connections is extracts. Extracts copy the data from the underlying data source and extract them to Tableau’s high-performance analytic data engine, Hyper. We will be looking at extracts and the Hyper engine in the next section of this chapter.

Live connections might seem like the obvious choice as they ensure the data is up to date and they don’t require the moving of data. Another good, and sometimes necessary, use case for live connections is when the data engine...