Calculated Fields and LODs Flashcards

Which calculation type would you use to compute a percent-of-total that updates as filters change the visible data?

Answer: Table calculation (Percent of Total)

A Percent of Total table calculation recomputes based on the marks visible in the view after filtering.

What does the function ZN([Profit]) accomplish in a calculated field?

Answer: Returns 0 when the value is null, otherwise the value

ZN replaces null values with zero, preventing gaps in calculations.

Which LOD direction is correct: INCLUDE produces a result at a ___ grain than the view?

Answer: Finer (more granular)

INCLUDE adds dimensions, computing at a finer grain before aggregating back up to the view.

What is wrong with mixing an aggregate and a non-aggregate in one expression, like SUM([Sales]) - [Profit]?

Answer: Tableau requires consistent aggregation; it errors

You cannot mix aggregated and row-level fields directly; both must be at the same level.

Which function lets you reference a value from a previous row in a table calculation?

Answer: LOOKUP()

LOOKUP returns the value of an expression offset from the current row in the partition.

How do you turn an aggregate LOD into a dimension for use as a discrete grouping?

Answer: Wrap it appropriately so it returns a row-level value, e.g. with FIXED

A FIXED LOD returns a value at a defined grain that can act as a dimension (e.g., customer-level cohort).

What does the calculated field WINDOW_AVG(SUM([Sales])) compute?

Answer: The average of SUM(Sales) across the window of marks

WINDOW_AVG averages the aggregated measure over a defined window of marks in the view.