So you're still fine as long as you're not tracking things that were deleted on that exact instant 50 years ago, a safe assumption, for instance, for things tha

So you're still fine as long as you're not tracking things that were deleted on that exact instant 50 years ago, a safe assumption, for instance, for things that happened in your application that has only existed for less time than that. That said, I haven't ever seen this implemented in a way that casts. It's implemented with scopes in the ORM, usually. MyModel.nondeleted.where(<criteria>) etc. which generates a query with "WHERE deleted_at IS NULL" 1-1-1970 is fine.