You can use rank with window function. Rank=1 is same as calling first(). Not sure how you would randomly pick records though, if there is no Nth record. In your example, what happens if data is of only 2 rows? On 27 Jul 2016 00:57, "Alex Nastetsky" <alex.nastet...@vervemobile.com> wrote:
> Spark SQL has a "first" function that returns the first item in a group. > Is there a similar function, perhaps in a third party lib, that allows you > to return an arbitrary (e.g. 3rd) item from the group? Was thinking of > writing a UDAF for it, but didn't want to reinvent the wheel. My endgoal is > to be able to select a random item from the group, using random number > generator. > > Thanks. >
