Daniel Hutmacher has a post showing how to calculate medians and percentiles in T-SQL:

Medians as a concept are simple enough. If you have a large number of values, like a range of statistical values, you want to pick the middle one. The

median, as opposed to theaverageis useful for a number of reasons, one of them that you can reduce the effect of so-called outlier values.

The fact that SQL Server doesn’t have a fast, built-in median function surprises me, to be honest. The best alternative I’ve found was a CLR function in SQL#.

Kevin Feasel

2016-02-22

T-SQL