
How Tableau Prep caches data When you connect to a data source in Tableau Prep, you will notice that you don’t have the option to select between a live or extract connection like in Tableau Desktop. You can use the default sample amount or build a sample set by specifying a fixed number of rows. Sampling ensures responsiveness to keep you in the flow of your task, even when you are working with large amounts of data in Tableau Prep.

At times, Tableau Prep may also sample your data. For example, if you join two tables together in a Join step, you will see the final join result-down to the number of rows-immediately. Interactive Mode delivers direct, interactive feedback as you clean, combine, and reshape your data. Building your flow with Tableau Prep When you are cleaning your data in any of the available step types (Clean, Union, Join, etc.), you are in what we call Interactive Mode in Tableau Prep. In this post, we'll get into the details of what is happening behind the scenes in Tableau Prep, so that you can navigate building and running flows with confidence. Tableau Prep is equipped with three modes that work to make your flows as optimized and performant as possible, without bogging down your machine or underlying database.

The Tableau Community is made up of smart, curious, data rock stars and we often get questions like, “Is Tableau Prep making a live connection to my data?” While that’s a relatively straightforward question to answer when we’re talking about Tableau Desktop, things work a little bit differently in Tableau Prep. Tableau Prep shifts this paradigm by bringing self-service data preparation to everyone, rather than just those with specialized skills. The Harvard Business Review even found that many analysts spend 80% of their time preparing their data, spending only 20% of time for analysis. From working with customers over the years, we hear, anecdotally, that cleaning data for analysis is a cumbersome process. In our role as solution engineers at Tableau, we get hands-on with customers every day, and get to see how companies - big and small - use Tableau Prep to clean and prepare their data.
