Tableau LOD expressions and data granularity

In this blog, I will have a short and general look at various levels of data granularity with Tableau’s Level of Detail Expressions. This is a brief summary about Data Granularity, level of details expressions and order of operations in Tableau.

**Granularity**

Data granularity is the level of detail in a model or decision-making process. It tells you how detailed your data is.

When we aggregate the data, we take multiple values and present them as a single value, so we decrease the level of detail. For example, the total sum of sales is 268K in all regions and years, is a high-level aggregation. When we add dimensions to the table, such as Region and Years, we increase the data granularity and increase the number of data points in our view.

**LOD Expressions in Tableau**

LOD expressions – Tableau’s elegant and powerful way to easily compute aggregations that are not at the level of detail of the visualization. There are 3 LOD functions: FIXED, INCLUDE and EXCLUDE. Through these functions you control the level of detail at which a calculation is performed and do not depend on dimensions used in the visualization. Letâ€™s summaries the 3 LOD functions:

**FIXED: Calculating at an exactly specified level of detail**

**Examples:**

- Calculating Measures between various time dimensions:

{FIXED [Week]: sum (Sales)}

- Calculating per Categories:

{FIXED [Product]: sum (Cost)} / {FIXED: sum (Cost)}

- Computing First or last data point per data subject:

{FIXED [Customer]: Min (Order Date)}

**INCLUDE: Calculating at a lower level of detail**

**Examples:**

- Calculating at a closer level of detail than in database:

{INCLUDE [Product], [Region]: sum (Sales)}

**EXCLUDE: Calculating at a higher level of detail**

**Examples:**

- Calculating at a larger level of detail than the one present in the view

{EXCLUDE [Product], [Region]: sum (Sales)}

**Order of operations in Tableau:**

If we have a quick look at Tableauâ€™s order of operations, Tableau executes the filters in the calculations, starting with the extract filters, and then going from top to bottom.

https://help.tableau.com/current/pro/desktop/en-us/order_of_operations.htm

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