Every TenantConfig belongs to one tenant, and tenantId records which one. Because the field is marked unique, a tenant can have at most one configuration record — there is a strict one-to-one relationship between a tenant and its settings. You never set this value by hand; Relic derives it from the authenticated session. The tenantId backs the relation to the parent Tenant, which exposes the configuration as its config field, so the settings travel with the tenant they govern.
Technical section
Data model, API, and internals — visible to developers.