Hi, Naomi, just a question - for a composite sort definition in the first ORDER BY (on the OrderDate and PurchaseOrderID), to handle multiple orders in the same day where you want to grab them in succession, is the ROWS UNBOUNDED PRECEDING necessary? I was under the impression that in 2012, if ROWS UNBOUNDED wasn't specified, you'd get the behavior of UNBOUNCED PRECEDING up to the current row.

If the ORDER BY is simply on ORDER DATE in this example, then yes, it seems it's definitely needed.

Thanks again.