Multi-Tenant Database Architecture for SaaS: PostgreSQL vs MongoDB for Scale

The 3 Multi-Tenancy Patterns Compared

• Database-per-Tenant: Maximum compliance and data isolation, ideal for enterprise healthcare and banking clients. Higher operational overhead when managing thousands of databases.
• Schema-per-Tenant (PostgreSQL): Strong logical isolation with shared physical resources. Clean migration paths and simplified maintenance.
• Shared Table with Row-Level Security (RLS): Maximum resource utilization and lowest hosting costs. PostgreSQL native RLS guarantees that tenant queries are cryptographically partitioned at the database engine level.