Django Multi-Tenancy — Schema-based vs. Database-per-Tenant

In today’s SaaS-driven world, building apps that serve multiple tenants (clients) securely and efficiently is essential. Whether you’re building a CRM, project management tool, or investment platform, chances are you’re dealing with multi-tenancy. But how do you implement it cleanly in Django? Should you use a single database or separate ones per client? In this article, we’ll take a deep dive into multi-tenancy in Django, exploring schema-based vs. database-per-tenant models, the trade-offs, and how to choose the right one.

🚪 What is Multi-Tenancy? Multi-tenancy is a software architecture where a single instance of your application serves multiple tenants, each with isolated data and configuration. Think of tenants as companies, organizations, or clients using the same app. Each should feel like they’re the only one using the app, but behind the scenes, you’re managing all of them efficiently.

🌍 The Three Main Multi-Tenancy Models

• Shared Database, Shared Schema — All tenants use the same tables, and you differentiate using a tenant_id field.
• Shared Database, Isolated Schemas — Each tenant has a separate schema (PostgreSQL feature).
• Separate Databases — Each tenant gets a dedicated database.

In Django, the last two — Schema-based and Database-per-Tenant — are the most robust and scalable. Let’s focus on those.

🏗️ Schema-based Multi-Tenancy This approach uses one database, but each tenant has their own schema (a namespace for their tables). PostgreSQL is a popular choice for this because of its robust schema support. ✅ Pros:

• Efficient resource usage — one DB connection pool, one DB server.
• Faster tenant creation — just create a new schema, run migrations.
• Shared codebase and infrastructure — simplifies maintenance.
• Centralized backups — you can snapshot all tenants at once.

❌ Cons:

• PostgreSQL-only — most relational DBs don’t support schemas like Postgres does.
• Cross-tenant queries are tricky — need raw SQL or schema switching.
• Complex migrations — need to run migrations across all schemas.

🔧 Django Packages:

• django-tenants
• django-tenant-schemas (older, archived)

🛢️ Database-per-Tenant Each tenant has a dedicated database, either on the same DB server or on separate servers. ✅ Pros:

• Maximum data isolation — great for compliance-heavy industries.
• Flexible scaling — you can move big tenants to faster servers.
• Independent backups — back up or restore individual tenants.
• Cross-tenant safety — no chance of leaking data between tenants.

❌ Cons:

• More operational overhead — managing many DBs, connections, credentials.
• Resource consumption — each DB instance adds memory/load.
• Complex connection logic — your app must dynamically switch DBs.

🔧 Django Packages:

• No “official” one-size-fits-all solution. You often use:
• Custom DatabaseRouters
• Connection switching via django.db.connections
• Connection pooling (e.g., PgBouncer)

⚖️ How to Choose the Right Approach? Ask yourself:

• Using PostgreSQL?
Go Schema-Based — ✅ Yes
Go Database-per-Tenant — ✅ Yes / ❌ No
• Need strong tenant data isolation?
Go Schema-Based — ⚠️ Moderate
Go Database-per-Tenant — ✅ Strong isolation
• Expect > 1,000 tenants?
Go Schema-Based — ✅ Easier to scale
Go Database-per-Tenant — ❌ Can get messy
• Regulatory / compliance-heavy?
Go Schema-Based — ❌ May not be enough
Go Database-per-Tenant — ✅ Better for compliance
• Simpler dev ops preferred?
Go Schema-Based — ✅ Fewer moving parts
Go Database-per-Tenant — ❌ More ops management

💡 Real-World Use Cases

• Schema-based: Ideal for B2B SaaS apps with many small/medium tenants (e.g., schools, startups).
• Database-per-tenant: Perfect for enterprise-grade apps with large tenants needing strict isolation (e.g., healthcare, banking).

⚙️ Bonus: How Django Handles It Django doesn’t support multi-tenancy out of the box, but it’s flexible. You can:

• Override middleware to set the tenant context from domain/subdomain.
• Write TenantMiddleware to control schema or DB selection.
• Use tenant-aware models and routers.

These patterns, while advanced, can scale beautifully with Django’s ORM power.

🚀 Wrapping Up Multi-tenancy is a core part of building scalable, modern SaaS applications. Django, when paired with the right tools and architecture choices, can handle it elegantly. Whether you go with schema-based or database-per-tenant, the key is choosing the model that aligns with your:

• Business model
• Compliance needs
• Operational capacity

Remember: it’s not just about code — it’s about long-term maintainability, security, and user trust.

Read the full article here: https://medium.com/@priyanshu011109/django-multi-tenancy-schema-based-vs-database-per-tenant-8602bb9e8862