SaaS applications need to isolate data from different tenants. PostgreSQL offers several strategies for multi-tenancy.

Isolation Strategies

There are three main approaches: database per tenant, schema per tenant, or shared schema with tenant_id column.

Schema per Tenant

Each tenant has its own schema. This offers good isolation with moderate cost.

CREATE SCHEMA tenant_123; SET search_path TO tenant_123;

Shared Schema

All data in one schema, separated by tenant_id. More efficient for many small tenants.

Our Choice

We use separate schemas per domain (blog, food, business) within a shared database. This balances isolation and efficiency.

Conclusion

The choice depends on tenant size, isolation requirements, and operational complexity.