The DAX functions RELATED and RELATEDTABLE are used to traverse relationships between tables to access data. Frequent use of these functions can indicate a highly normalized model, which may lead to complex DAX and potential performance issues. Merging tables in Power Query is a denormalization technique. By combining related tables into a single, wider table, the required columns become directly accessible within the same table context. This eliminates the need to use RELATED or RELATEDTABLE to navigate relationships, thereby simplifying the DAX expressions and often improving model performance.

B. Hiding columns only affects the report view for end-users. It does not change the underlying model structure or the need for DAX to traverse relationships for calculations.

C. Splitting the model into multiple models is a scalability strategy for very large datasets. It increases overall complexity and does not simplify the DAX within each model.

D. Transposing is a specific data shaping operation that swaps rows and columns. It is irrelevant to simplifying DAX expressions that depend on table relationships.

1. Microsoft Learn: Understand star schema and the importance for Power BI. In the section "Denormalize snowflake dimensions

" the documentation states

"A snowflake dimension should be denormalized into a single table... You can use Power Query to consolidate the columns... It's a process of denormalization." This directly supports merging tables to simplify the model.

2. Microsoft Learn: Merge queries (Power Query). This document describes the technical process of merging

which is the implementation of the recommended solution. It states

"a merge query joins two existing tables together based on matching values from one or multiple columns."

3. Microsoft Learn: DAX function reference: RELATED. The documentation for the RELATED function specifies that it "requires that a relationship exists... When the function follows a relationship... it examines the value... and fetches the value... from the specified column in the related table." This confirms that by merging

the need for the function is removed as the data is no longer in a "related table."