[throwaway7783]

Works when there is always an active price. Having an explicit end date allows certain rows to be inactive automatically after validity period. Think of seasonal categories/products etc which dont exist after a specific period

[promano]

And even if you don't have seasonal products, you still need an end date to mark when you stop selling a product; otherwise you have to do something hacky like defining "<price> = NULL means we stopped selling the product after <valid_from>" and inserting an extra record.

I think the end date should be nullable though, but valid_to is NOT NULL in the starting example... later in the article, when showing the "new way" using date ranges, it inserts a row with an open-ended range, which is more what I'd expect.

[larsnystrom]

You could also make the price column nullable and just insert a row with price null and the date from which there should be no price.

[throwaway7783]

Yeah, but now this is implicit information (no price == marker row) and duplicate the entire row. And it is baking in "price" as the special field. This may not be just one field for another temporal entity