In SaaS multi-tenant database design, do you think it is sufficient to include the tenant id only in top-level resources, knowing that child resources will always be parent-scoped, or should every table include
tenant_id as a foreign key?
For example, if
Projects that have
Tasks, is it enough to specify
Projects.tenant_id and only
Tasks.project_id, because Tasks will "always" be fetched via their corresponding Project?
Or should Tasks (and every other table) include
tenant_id without exception?