PL-300 Model the data Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  TotalSalesLast30Days = CALCULATE(SUM(Orders[TotalAmount]), FILTER(Orders, Orders[OrderDate] > TODAY() - 30), FILTER(Orders, CALCULATE(COUNTROWS(Orders), ALLEXCEPT(Orders, Orders[CustomerID])) > 5))

  Why it's wrong here

  This approach uses two separate FILTER arguments inside CALCULATE, each iterating the entire Orders table. The second FILTER's expression, which calls CALCULATE with ALLEXCEPT, forces a context transition on every row, recomputing the customer's order count repeatedly; this is computationally expensive and can cause subtle row-context issues because the two FILTERs are evaluated independently and then combined with an implicit AND. Consequently, the measure may produce the correct result in small tables but performs poorly and is harder to debug.

• ✗

  TotalSalesLast30Days = CALCULATE(SUM(Orders[TotalAmount]), KEEPFILTERS(Orders[OrderDate] > TODAY() - 30), KEEPFILTERS(CALCULATE(COUNTROWS(Orders), ALLEXCEPT(Orders, Orders[CustomerID])) > 5))

  Why it's wrong here

  The expression tries to use KEEPFILTERS around a logical comparison that contains a nested CALCULATE, which is not a valid filter argument inside CALCULATE. In DAX, a filter passed to CALCULATE can be a table expression or a Boolean expression, but wrapping `CALCULATE(COUNTROWS(...), ALLEXCEPT(...)) > 5` in KEEPFILTERS does not make it a valid predicate; it produces a syntax or evaluation error. The correct pattern must use FILTER to iterate rows before evaluating the count, or use a separate measure with a calculated column.

• ✓

  TotalSalesLast30Days = SUMX(FILTER(Orders, Orders[OrderDate] > TODAY() - 30 && CALCULATE(COUNTROWS(Orders), ALLEXCEPT(Orders, Orders[CustomerID])) > 5), Orders[TotalAmount])

  Why this is correct

  This is the correct answer because it uses a single SUMX iterator over a FILTERed table, where the filter expression evaluates both conditions in one row context. Inside the filter, `CALCULATE(COUNTROWS(Orders), ALLEXCEPT(Orders, Orders[CustomerID]))` correctly counts all rows for the same customer, avoiding any interference from the date filter on the outer row, and the AND ensures only customers with more than five orders and a recent order date are included. SUMX then sums the TotalAmount across those qualifying rows, directly matching the requirement while remaining efficient and maintainable.

• ✗

  TotalSalesLast30Days = CALCULATE(SUM(Orders[TotalAmount]), DATESINPERIOD(Orders[OrderDate], TODAY(), -30, DAY))

  Why it's wrong here

  This measure filters only by a date window using DATESINPERIOD relative to TODAY(), producing a date range of the last 30 days. However, it completely omits the required customer-level condition—that the customer must have more than five orders within that same period—so it returns total sales for all customers, not just qualifying ones. Moreover, DATESINPERIOD shifts the range as a static period and does not dynamically filter per customer, so the measure fails the stated requirement.

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