>>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.
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>>If the ORDER BY is simply on ORDER DATE in this example, then yes, it seems it's definitely needed.
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>>Thanks again.
>
> I believe UNBOUND PRECEDING is the default, so I didn't need to specify it explicitly.

Well, like I said, if the definition of the ORDER BY has a unique granularity whose order you would deem chronologically sequential (i.e. a PurchaseOrderID), then I don't think it's necessary. But if the ORDER BY was just on the Order Date (a date column ), then I believe it's needed.

But aside from that, it's great that MS now has a way to implementing accumulating values that's (comparatively) less costly.