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Tableau Prep FAQs

Tableau Prep is an invaluable tool for transforming and cleaning data before creating visualizations in Tableau. However, knowing the right techniques and avoiding common mistakes is essential for ensuring smooth and efficient workflows. 

This job aid covers important do’s and don’ts in Tableau Prep, and highlights key limitations, like compatibility issues with Tableau’s relationship model and the tool’s lack of real-time data analysis capabilities. Whether you're a beginner or an experienced user, these tips will help you avoid common pitfalls and optimize your data prep process.

Tableau Prep Do’s

  1. Filter Out Irrelevant Data Early
    To avoid unnecessary processing, filter out irrelevant rows and columns at the beginning of your flow. This can be done directly in the SQL WHERE clause or immediately after the data source is connected to Tableau Prep.
  2. Understand SQL and Joins/Unions
    Having a basic understanding of SQL is essential, especially when working with joins and unions. Knowing when to use each operation can streamline your data transformation process and reduce errors.
  3. Use Comments for Documentation
    To make your flows more transparent and maintainable, add comments to key steps. This helps other users understand the logic behind the data transformations and keeps your workflow organized. Comments are limited to 200 characters.

Tableau Prep Don’ts

  1. Don’t Overload with Large Datasets Multiple Times
    Be mindful of adding the same large datasets (a few million rows) more than once. For example, don’t import the same employee data multiple times in separate steps, as this can result in redundancy and inefficiency.
  2. Don’t Expect Real-Time Data Analysis
    Tableau Prep is designed primarily for data preparation and cleaning, not for real-time data analysis. While you can explore the data, it’s not optimized for quick insights or live data feeds.
  3. Don’t Assume Compatibility with Tableau’s Relationship Model
    Tableau Prep doesn’t support Tableau’s relationship model, which can be an issue for datasets like the [CERTIFIED] Workday Journal Line data set. It is not the role of subject matter experts, the Data Visualization team, or others to convert Tableau data sources for Prep. For complex use cases like these, users need a solid understanding of SQL and direct access to the RAE (Reporting and Analytics Environment).
  4. Avoid Complex Flows
    Tableau Prep can struggle with complex flows, especially those with more than a dozen steps. These flows often break or become difficult to manage. Simplifying your workflows can help ensure more reliable results.
  5. Don’t Rely on Tableau Prep for Bug-Free Experiences
    While Tableau Prep is a robust tool, it’s not always supported with the same level of attention as Tableau Desktop. You might encounter bugs that require patience or waiting for updates.

Additional Tableau Prep Tips