Tableau Prep: Up & Running

Chapter 24. Removing Data During Input

You can simplify a lot of your data preparation work by making changes to the initial data connection, which is created and shown in the Input step in Prep Builder. However, you often know that certain elements in your data set need to be changed or removed even before you input it into Prep Builder. This chapter will cover some considerations for removing data at that early stage and how you might go about doing so.

Changing Your Data Set Before Loading It

Data sets are proliferating and growing rapidly, so you have to think carefully about what is actually being loaded into the tool. Any input data will be loaded into your computer’s memory, so any effort to reduce the amount of data that has to be processed will be useful. Prep Builder will sample the data set on the initial load, processing the full data set only when you run the output.

For Prep Builder, the initial connection is the Input step, but Prep Builder doesn’t load in all of the data instantly. Prep will load the metadata—the data about the data—in the Input step first. This helps end users in two ways:

• Providing a quick overview of the data

• Preventing slow load times, since Prep Builder isn’t having to process all of the data

Deselecting the fields that you and the end users do not require will save that data from being processed by Prep Builder (Figure 24-1).

Figure ...