Managing RLS in Service in Power BI - Cell-by-Cell Formula Trace

Sample Data

This table shows users and their assigned regions for Row-Level Security (RLS) in Power BI Service.

Cell	Value
A1	User
B1	Region
A2	Alice
B2	North
A3	Bob
B3	South
A4	Carol
B4	East
A5	Dave
B5	West

Formula Trace

USERNAME() = "Alice" && [Region] = "North"

Step 1: USERNAME()

Step 2: [Region]

Step 3: USERNAME() = "Alice"

Step 4: [Region] = "North"

Step 5: TRUE && TRUE

Cell Reference Map

    A       B
1 | User  | Region
2 | Alice | North  <-- USERNAME() matches 'Alice', Region is 'North'
3 | Bob   | South
4 | Carol | East
5 | Dave  | West

The formula uses USERNAME() to get the current user and compares it to 'Alice'. It also checks the Region column in the current row.

Result

    A       B
1 | User  | Region
2 | Alice | North  <-- Visible to Alice
3 | Bob   | South  <-- Not visible to Alice
4 | Carol | East   <-- Not visible to Alice
5 | Dave  | West   <-- Not visible to Alice

Because the RLS rule allows only rows where USERNAME() is 'Alice' and Region is 'North', Alice sees only her row.

Sheet Trace Quiz - 3 Questions

What does USERNAME() return in the formula?

A The region name

B The table name

C The current logged-in user name

D The current date

Key Result

RLS filters rows by checking if USERNAME() matches the user and the row's attribute matches the allowed value.

Practice

1. What is the primary purpose of Row-Level Security (RLS) in Power BI Service?

easy

A. To change the report layout based on user preferences

B. To improve report loading speed by caching data

C. To create new data columns dynamically in reports

D. To restrict data access so users see only data they are allowed to view

Solution

1. Step 1: Understand RLS purpose

   RLS is designed to limit data visibility for different users based on roles.

2. Step 2: Identify correct purpose in options

   Only To restrict data access so users see only data they are allowed to view describes restricting data access to authorized users.

3. Final Answer:

   To restrict data access so users see only data they are allowed to view -> Option D

4. Quick Check:

   RLS controls data visibility = D [OK]

Hint: RLS controls who sees what data in reports [OK]

Common Mistakes:

• Confusing RLS with report performance features
• Thinking RLS changes report design
• Assuming RLS creates new data columns

2. Which step must be done in Power BI Service after defining roles in Power BI Desktop to enforce RLS?

easy

A. Assign users or groups to the defined roles

B. Create new calculated columns for roles

C. Publish the report again without changes

D. Change the data source credentials

Solution

1. Step 1: Recall RLS workflow

   After defining roles in Desktop, you must assign users to those roles in Service.

2. Step 2: Match correct action in options

   Only Assign users or groups to the defined roles describes assigning users to roles, which activates RLS.

3. Final Answer:

   Assign users or groups to the defined roles -> Option A

4. Quick Check:

   Assign users to roles in Service = A [OK]

Hint: Assign users to roles in Service to activate RLS [OK]

Common Mistakes:

• Thinking you must create columns for RLS in Service
• Assuming republishing alone enforces RLS
• Confusing data source credentials with RLS setup

3. Given a role defined with filter [Region] = "West", what data will a user assigned to this role see in the report?

medium

A. Data from all regions without filtering

B. All data except Region West

C. Only data where Region is West

D. No data will be visible

Solution

1. Step 1: Understand role filter meaning

   The filter [Region] = "West" limits data to rows where Region equals West.

2. Step 2: Determine visible data for user

   User assigned to this role sees only data matching the filter, i.e., Region = West.

3. Final Answer:

   Only data where Region is West -> Option C

4. Quick Check:

   Role filter = visible data = C [OK]

Hint: Role filters show only matching data rows [OK]

Common Mistakes:

• Assuming filter excludes matching data
• Thinking user sees all data regardless of filter
• Believing filter hides all data

4. You assigned users to roles in Power BI Service but they still see all data. What is the most likely issue?

medium

A. Users were assigned to roles correctly

B. Roles were not published from Power BI Desktop

C. Data source credentials are invalid

D. Report visuals are not refreshed

Solution

1. Step 1: Check role publishing status

   Roles must be defined and published from Desktop to Service for RLS to work.

2. Step 2: Identify why users see all data

   If roles are not published, assignments in Service have no effect, so users see all data.

3. Final Answer:

   Roles were not published from Power BI Desktop -> Option B

4. Quick Check:

   Roles must be published for RLS to apply = A [OK]

Hint: Publish roles from Desktop before assigning users [OK]

Common Mistakes:

• Assuming assigning users alone activates RLS
• Blaming data source credentials for RLS issues
• Forgetting to refresh report visuals

5. You have two roles: SalesWest with filter [Region] = "West" and SalesEast with filter [Region] = "East". A user belongs to both roles. What data will they see in the report?

hard

A. Data where Region is West or East

B. Data where Region is both West and East simultaneously

C. Only data from the first assigned role

D. No data because roles conflict

Solution

1. Step 1: Understand multiple role behavior

   When a user has multiple roles, Power BI combines filters with OR logic.

2. Step 2: Apply OR logic to role filters

   User sees data where Region = West OR Region = East, so both regions' data are visible.

3. Final Answer:

   Data where Region is West or East -> Option A

4. Quick Check:

   Multiple roles combine filters with OR = B [OK]

Hint: Multiple roles combine filters with OR logic [OK]

Common Mistakes:

• Thinking filters combine with AND logic
• Assuming only one role applies
• Believing conflicting roles block all data