Part 147: Row-Level Security (RLS) for Multi-Tenant Apps

Enforcing tenant isolation directly at the database engine level so Tenant A can never see Tenant B's data, even if application code forgets a WHERE clause!

1. Configuring RLS in PostgreSQL

ALTER TABLE documents ENABLE ROW LEVEL SECURITY;

CREATE POLICY tenant_isolation_policy ON documents
  FOR ALL
  USING (tenant_id = CURRENT_SETTING('app.current_tenant_id')::BIGINT);

Key Takeaways

• RLS provides impenetrable security in multi-tenant SaaS applications.

In Part 148, we explore SQL Injection (SQLi) Defense: Parameterized Queries!