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Implementing Row Level Security

Learn Implementing Row Level Security for free with explanations, exercises, and a quick test (for BI Developer).

Published: December 24, 2025 | Updated: December 24, 2025

Why this matters

As a BI Developer, you ship dashboards and datasets that many people access. Without Row Level Security (RLS), users could see data they shouldn’t — customer records, salaries, sales by other regions, or restricted projects. RLS lets you restrict rows based on who is querying, so each person sees only what they’re allowed to see.

  • Protect sensitive business data while enabling broad self-service analytics.
  • Reduce the need to clone datasets per audience.
  • Simplify governance with a single, secure semantic model.

Concept explained simply

RLS is a rule that says “only rows matching this condition are visible to this user.” The condition can use attributes like user email, role, department, or a mapping table of entitlements.

Mental model

Imagine every query automatically adds a hidden WHERE clause that matches the user’s permissions. For example: WHERE region IN (regions the user is allowed to see). If a row doesn’t match, it behaves as if it doesn’t exist for that user.

Key properties of good RLS
  • Deny-by-default: If uncertain, show nothing.
  • Centralized entitlements: One source of truth mapping users to allowed data.
  • Dynamic: No manual updates when people move teams.
  • Auditable: Easy to check who can see what.
  • Testable: You can impersonate users safely.

Core patterns

  • Predicate-based RLS: A rule that filters rows by a condition (e.g., country = user_country).
  • Entitlement-table join: Maintain a table listing (principal, data_key) pairs; join to filter.
  • Role-based filters in BI tools: Define roles/expressions that use the viewer’s identity.

Worked examples

Example 1 — SQL entitlement table (generalized)

Goal: Only show orders from regions a user is entitled to.

-- Entitlements: which user can see which region
CREATE TABLE entitlements (
  principal_id VARCHAR,  -- e.g., user email or group id
  region       VARCHAR
);

-- Fact table
CREATE TABLE orders (
  order_id INT,
  region   VARCHAR,
  amount   NUMERIC
);

-- RLS concept: filter orders by a join to entitlements for the current principal
-- Pseudocode for a secured view (replace CURRENT_PRINCIPAL with your platform’s function)
CREATE OR REPLACE VIEW orders_secured AS
SELECT o.*
FROM orders o
JOIN entitlements e
  ON e.region = o.region
WHERE e.principal_id = CURRENT_PRINCIPAL();

Queries against orders_secured only return rows where the principal has matching entitlements. Deny-by-default is achieved because rows without matching entitlements are filtered out.

Testing this example
  1. Insert sample entitlements for two users.
  2. Impersonate or set CURRENT_PRINCIPAL to each user.
  3. SELECT * FROM orders_secured and verify regions match the entitlement table for that user.

Example 2 — BI role filter (semantic model)

Many BI tools support row filters referencing the current viewer. You define a role and an expression that uses the logged-in user identity.

-- Pseudocode logic for a model filter on a Region dimension:
Region[Region] IN VALUES(Entitlements[Region])
AND Entitlements[Principal] = CURRENT_USER()

Attach the role to your dataset/model, and ensure users access the model with their identity. The model automatically restricts rows across all visuals — not just individual charts.

Tips for this approach
  • Reference a single Entitlements table used by all models.
  • Avoid hard-coded user emails in filters; rely on a table and CURRENT_USER().
  • Keep your grain consistent: Region vs Country vs Store.

Example 3 — Hierarchical org security (manager sees team)

Scenario: A manager can see their own data and their direct/indirect reports. Use a parent-child org table and expand it for entitlements.

-- org_hierarchy: employee -> manager 
CREATE TABLE org_hierarchy (
  employee_id VARCHAR,
  manager_id  VARCHAR
);

-- Build a manager_to_employee mapping (transitive) into entitlements
-- (This can be materialized in ETL)
CREATE TABLE entitlements AS
SELECT m.manager_id AS principal_id,
       e.employee_id AS data_key
FROM org_hierarchy e
JOIN RECURSIVE_EXPAND(e.employee_id, e.manager_id) AS h -- pseudo recursive expansion
  ON ...
-- Then filter facts by employee_id IN (data_key for CURRENT_PRINCIPAL)

Result: Managers see their team’s rows; individual contributors see only their own.

Implementation checklist

  • Define data domains and access rules (who should see what, at what grain).
  • Create a single Entitlements table: principal_id, data_key (and optionally scope, start/end dates).
  • Implement deny-by-default logic via joins or policies.
  • Use the platform’s identity function (e.g., current user) in filters.
  • Test with user impersonation for edge cases.
  • Add indexes/cluster keys on entitlement join columns to keep queries fast.
  • Set up monitoring: number of rows returned by role, unexpected full scans, policy bypass attempts.

Exercises

Do these in order. Use sample data or adapt to your environment.

Exercise 1 — Build a secured view with entitlements

Mirror of Exercise ex1 below.

Steps
  1. Create orders and entitlements tables.
  2. Insert data for at least two users and two regions.
  3. Create a secured view that filters by CURRENT_PRINCIPAL.
  4. Test by impersonating each user and verifying allowed rows.

Exercise 2 — Add dynamic RLS to a BI model

Mirror of Exercise ex2 below.

Steps
  1. Load Orders, Region, and Entitlements into a model.
  2. Define a role that filters Region by Entitlements for CURRENT_USER.
  3. Validate with a simple table visual and user impersonation.

Self-check checklist

  • Deny-by-default: Users see nothing if not in entitlements.
  • Central table: No hard-coded users in filters.
  • Impersonation tests: At least three identities tested.
  • Edge cases: User with multiple regions, user with none, manager hierarchy.
  • Performance: Queries still fast after RLS is enabled.

Common mistakes and how to self-check

  • Putting filters only on visuals instead of the model. Fix: Implement model-level RLS so all visuals inherit it.
  • Hard-coding user emails in rules. Fix: Use an entitlement table and CURRENT_USER.
  • Inconsistent grain between entitlements and facts. Fix: Align grain (e.g., both at Region) or map via conformed dimensions.
  • No deny-by-default. Fix: Ensure unmatched users get zero rows.
  • Skipping tests for power users/admins. Fix: Impersonate them; verify least privilege still holds.
  • Performance regressions from many-to-many joins. Fix: Index keys, pre-aggregate entitlement expansions, or materialize secured views.

Practical projects

  • Single-model security: Add RLS to a sales dataset using a Region entitlement table; document your rules.
  • Org hierarchy: Build dynamic manager access (team rollup) and a test matrix (manager, IC, contractor).
  • Audit & monitoring: Create a small report showing row counts returned per role/user and alert on anomalies.

Learning path

  1. Understand identity: what user attribute your platform exposes (email, ID, groups).
  2. Model entitlements: design principal-to-data mappings at the correct grain.
  3. Implement in SQL/warehouse first, then in the BI model.
  4. Add tests and impersonation scripts.
  5. Harden and monitor performance and coverage.

Who this is for

  • BI Developers building shared datasets/dashboards.
  • Analytics Engineers designing secure semantic layers.
  • Data Stewards/Governance partners defining access rules.

Prerequisites

  • Comfort with SQL JOINs and dimension modeling.
  • Basic knowledge of your BI tool’s role/security features.
  • Access to a test environment where you can impersonate users.

Next steps

  • Complete the exercises, then take the Quick Test below.
  • Apply RLS to a real, non-critical dataset in your environment.
  • Document your entitlement model and rollout plan.

Mini challenge

Design RLS for a dataset where some users see their stores, district managers see all stores in their district, and HQ analysts see all. Implement with a single entitlement structure and deny-by-default. Validate with three impersonated users.

Quick Test

Take the quiz to check your understanding. Everyone can take it for free; logged-in users will have their progress saved automatically.

Practice Exercises

2 exercises to complete

Instructions

Goal: Users only see orders for regions they are entitled to.

  1. Create tables: orders(order_id, region, amount) and entitlements(principal_id, region).
  2. Insert sample data for two users (e.g., ana@corp sees North, ben@corp sees South).
  3. Create a view orders_secured that joins orders to entitlements and filters by CURRENT_PRINCIPAL().
  4. Impersonate as each user and SELECT * FROM orders_secured. Record visible order_ids.
Expected Output
Each user sees only orders from their assigned region(s). Users without entitlements see zero rows (deny-by-default).

Implementing Row Level Security — Quick Test

Test your knowledge with 8 questions. Pass with 70% or higher.

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