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.

• ✓

  Change the data type of the OrderDate column to 'Date' in Power Query.

  Why this is correct

  Changing the data type of the OrderDate column to 'Date' in Power Query is the most efficient solution because it performs the conversion directly on the existing column during data load, using Power Query's native type system. This eliminates the time portion without adding a new column or increasing model size, and it ensures the column is properly date-typed for all downstream reports. The statement about being less explicit is misleading; altering the data type is the standard approach when you need to discard the time component.

• ✗

  Create a calculated column in DAX using DATEVALUE(OrderDate).

  Why it's wrong here

  Creating a calculated column in DAX using DATEVALUE(OrderDate) is less efficient than a Power Query transformation because the calculation runs after the data has been loaded into the model, increasing model size and refresh time. DATEVALUE relies on the locale and the stored date format, which can lead to unexpected results, and it does not leverage Power Query's optimized transformation engine that runs before data is loaded.

• ✗

  Create a new column in Power Query using Date.From(OrderDate).

  Why it's wrong here

  Creating a new column in Power Query using Date.From(OrderDate) is redundant and less efficient than changing the original column's data type, because it adds duplicate data to your model, increasing memory consumption and potentially confusing report users with two date-like fields. While Date.From is a valid function, the best practice is to transform the existing column in place so that your data model remains lean and consistent.

• ✗

  Use the 'Split Column' feature in Power Query to separate date and time.

  Why it's wrong here

  Using the 'Split Column' feature is an inefficient approach for this task because it divides the OrderDate column into two separate columns (date and time), requiring you to either delete one or combine them later. It introduces multiple extra steps and creates unnecessary data in your model, whereas simply changing the data type to Date accomplishes the same goal in one action. Additionally, splitting a datetime column may produce columns with inherited data types that need further attention.

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