Calculate unique count with reduce function _stats
Hi, I wanna calculate the amount of unique items I emitted to a _stats reduce function.
Is that possible? (I guess I only have these 2 useful variables 'sum' and 'sumsqr', because 'count' just tells me count of all emits I did.)
Or do I have to write a custom Mapreduce function?
Here's the output: (group=false)
Can someone give me an advice please?
Thank you very much