PL-300 · Question #454
You have a Power BI query named Expenses that imports the following data. Users only use the date portion of the TransactionDate value when performing data analysis. You need to minimize the model…
The correct answer is A. Change the data type of the TransactionDate column to Date. C. Remove the PostDate column. To minimize Power BI model size without affecting analysis when only the date portion of a datetime column is used, convert the column to a date data type and remove any other unnecessary date columns.
Question
You have a Power BI query named Expenses that imports the following data. Users only use the date portion of the TransactionDate value when performing data analysis. You need to minimize the model size without affecting the analysis. Which two actions should you perform? Each correct answer presents part of the solution. NOTE: Each correct selection is worth one point.
Exhibit
Options
- AChange the data type of the TransactionDate column to Date.
- BChange the data type of the PostDate column to Date.
- CRemove the PostDate column.
- DRemove the TransactionID column.
How the community answered
(28 responses)- A79% (22)
- B14% (4)
- D7% (2)
Why each option
To minimize Power BI model size without affecting analysis when only the date portion of a datetime column is used, convert the column to a date data type and remove any other unnecessary date columns.
Changing the data type of the TransactionDate column from 'datetime' to 'Date' removes the time component, which is explicitly stated as not being used for analysis, thereby reducing the cardinality and size of the column in the model.
Changing the data type of the PostDate column to Date is redundant if the column is to be removed, and even if kept, 'PostDate' is likely already a date type, so this action would have no impact on model size.
Removing the PostDate column minimizes the model size because the requirement states that users only use the date portion of the 'TransactionDate' value, implying that 'PostDate' is not needed for analysis and thus represents an unnecessary column.
Removing the TransactionID column would negatively affect analysis if unique transaction identification is ever required, and it is not explicitly stated as unnecessary for the given analysis, unlike the 'PostDate' column.
Concept tested: Power Query data type optimization, column removal for model size reduction
Source: https://learn.microsoft.com/en-us/power-bi/guidance/import-modeling-guidance#model-optimization
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