Getting The Last Row Per Group

Daniel Hutmacher wants to get the last element in each group (for example, the current records in a type-two dimension):

The CROSS APPLY and the old-school solutions are by far the best choice for dense indexes, i.e. when the first column has a low degree of uniqueness. The old-school solution is only that fast because the optimizer short-circuits the query plan.

LEAD() and the old school strategy are best for selective indexes, i.e. when the first column is highly unique.

There’s a nice set of options available so if one doesn’t work well with your particular data set, try out some of the others and see if they work for you.

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