single-database-tenant-isolation

Enforce tenant isolation in a single shared database by adding a NOT NULL tenant_id column to all tenant-scoped tables and applying ORM global scopes or repository patterns to automatically filter all queries by tenant_id.

Prevent cross-tenant data exposure by auditing your data model to classify tables as tenant-scoped or platform-level, adding tenant_id constraints with safe backfill migrations, and validating the isolation enforcement through comprehensive integration tests.

Yes, this approach requires schema changes: you must add tenant_id columns, implement leading-column indexes on tenant_id for all tenant-scoped queries, and apply not-null constraints through safe database migrations to ensure data integrity.

Handle safe admin access by designing specific cross-tenant access paths for platform operations that bypass the automatic tenant_id filtering, ensuring standard tenant queries remain strictly scoped while admins can retrieve global data securely.

Leading-column indexes on tenant_id are required to prevent performance degradation in tenant-scoped queries, ensuring the database efficiently filters data per tenant within the shared single-database architecture without scanning unrelated tenant rows.

You should reconsider a single-database multi-tenant architecture if your application requires absolute physical data separation between tenants, as this approach relies on logical tenant_id scoping and ORM filtering rather than physical database-level isolation.