# Tenant Hosting {#tenant-hosting}


MQUAD supports multiple tenant data isolation strategies to meet different compliance and scalability requirements.


## Isolation Strategies {#isolation-strategies}


| Strategy | Isolation | Cost | Complexity | Use Case |
|----------|-----------|------|------------|----------|
| Shared Database | Row-level | Low | Low | Small tenants, SaaS |
| Schema-per-Tenant | Schema-level | Medium | Medium | Medium tenants |
| Database-per-Tenant | Database-level | High | High | Enterprise, compliance |


## Shared Database (Default) {#shared-database-default}


All tenant data resides in the same database, isolated by `tenant_id` column:

```python
# Every query filters by tenant_id
query = select(Survey).where(Survey.tenant_id == request.state.tenant_id)
```

**Pros:** Simple, low overhead, easy to manage.  
**Cons:** No hard isolation boundary.


## Database-per-Tenant {#database-per-tenant}


For maximum isolation, each tenant gets dedicated databases:

```python
async def _create_tenant_databases_for_services(self, tenant_id: str):
    services = ["survey_db", "data_db", "workspace_db", ...]
    for base_db in services:
        tenant_db = f"{base_db}_tenant_{tenant_id.replace('-', '_')}"
        # CREATE DATABASE tenant_db
        # Run migrations on tenant_db
        # Register in tenant_metadata
```


### Naming Convention {#naming-convention}


```
{base_db}_tenant_{tenant_id_underscored}
```

Example: `survey_db_tenant_acme_org`


### Tenant Creation Flow {#tenant-creation-flow}


1. Create tenant record in `appdb.tenants`
2. Seed tenant roles (Admin, Editor, Viewer)
3. Create tenant databases across all services
4. Run Alembic migrations on each tenant database
5. Create admin user for tenant


## Configuration {#configuration}


Tenant isolation mode is configured via environment variables:

```bash
TENANCY_ENABLED=true
TENANT_DB_ISOLATION=database  # shared | database
```


## Frontend Routing {#frontend-routing}


```typescript
// Dashboard layout routes by tenant status
if (isDormant && isAdmin) -> /dormant-admin
if (isDormant && !isAdmin) -> /tenant-offline
if (!is_active) -> /non-active
```