Role-Based Access Control (RBAC) in Azure - Time & Space Complexity

Time Complexity: Role-Based Access Control (RBAC)

O(n)

Understanding Time Complexity

When managing access in Azure, it is important to understand how the time to assign roles grows as you add more users or resources.

We want to know how the number of role assignments affects the time it takes to apply permissions.

Scenario Under Consideration

Analyze the time complexity of assigning roles to multiple users.

// Assign a role to each user for a resource
foreach (var user in users) {
  azure.RoleAssignments.Create(
    scope: resourceId,
    roleDefinitionId: roleId,
    principalId: user.Id
  );
}
    

This code assigns the same role to each user on a specific resource one by one.

Identify Repeating Operations

Identify the API calls, resource provisioning, data transfers that repeat.

• Primary operation: Role assignment API call to Azure for each user.
• How many times: Once per user in the list.

How Execution Grows With Input

Each additional user requires one more API call to assign the role.

Input Size (n)	Approx. API Calls/Operations
10	10 role assignment calls
100	100 role assignment calls
1000	1000 role assignment calls

Pattern observation: The number of API calls grows directly with the number of users.

Final Time Complexity

Time Complexity: O(n)

This means the time to assign roles grows linearly as you add more users.

Common Mistake

[X] Wrong: "Assigning roles to multiple users happens all at once, so time stays the same no matter how many users there are."

[OK] Correct: Each role assignment is a separate API call, so more users mean more calls and more time.

Interview Connect

Understanding how role assignments scale helps you design access control that stays efficient as your team grows.

Self-Check

"What if we assigned roles to groups instead of individual users? How would the time complexity change?"