Can built-in and custom reduce functions be used together?
I have been trying to figure out how to use built-in reduce functions as part of my custom function. From the documentation here (Line 4: http://www.couchbase.com/docs/couchbase-devguide-2.0/creating-custom-red...) it seems it's possible. It says "There are however some cases where you will need to build a custom reduce function either alone, or in conjunction with a built-in reduce".
Consider an example where I want to compute standard deviation of the values emitted by my map function. Could I then as part of that reduce use _sum and _count to compute mean and then use that further?