Table Calculations, often referred to as table calcs in Tableau, are computations or calculations that are applied to the results of a query or aggregation in a Tableau visualization. The keyword "computation" is that makes these table calculations crutial and very supportive when performace should be increased.
These calculations are performed on the displayed data in a visualization, allowing you to create complex, context-aware insights and visualizations that go beyond what basic aggregation functions can provide.
"How?"
Key points to understand about Table Calculations:
Context-Aware Analysis: Table calculations take into account the dimensions and measures present in your visualization. They can consider the order of rows and columns, filter settings, and the current level of detail to perform calculations.
Computed on the Fly: Table calculations are calculated on the data as it's being displayed in the visualization, rather than on the dataset itself. This means that the result of a table calc can change dynamically based on the view and any interactions by the user.
Various Calculation Types: Tableau provides a wide range of predefined table calculations, such as running totals, percent of total, moving averages, and rank calculations, among others. These can be customized to meet your specific analytical needs.
Table Calculation Functions: Table calculations in Tableau are created using specific functions, such as WINDOW_SUM, WINDOW_AVG, and PREVIOUS_VALUE. These functions allow you to define how the calculation should be computed relative to the current and neighboring rows and columns.
Order of Operations: The order in which table calculations are computed is important and follows Tableau's Order of Operations. Understanding this order is essential for accurate calculations and results.
"When?"
Customization: You can create custom table calculations by combining existing functions and defining your logic. This enables you to tailor calculations to your unique requirements.
Visual Enhancements: Table calculations are often used to enhance the visual representation of data in Tableau, allowing you to create features like trend lines, reference lines, conditional formatting, change of color, action interactions and more.
Advanced Analytics: Table calculations are a powerful tool for performing advanced analytics and exploring complex patterns, trends, and relationships within your data which allow you to get more insights.
In summary, Table Calculations in Tableau are a set of flexible and dynamic calculations that provide context-aware insights into your data. Sets are very underrated and not really used as are considered "comples" and allow you to adapt to the context of your analysis, making them a valuable tool for data exploration and storytelling.