view processing isn't incremental enough in the face of failures making it hard to work with

I have a map() function which emits a number. Only at reduce time does it fail. I don't think it should fail, but that's filed as a separate bug.

In this request for enhancement, I think it'd be great if the system could be more reliable in the face of some items not being processed. If the map or reduce fail for a given document, it's not possible to get results from the ones that were processed well. For use cases such as mine (and for which the "tunable memory" feature was added in 3.0.1) where I'm sampling, it'd be perfectly fine to get results along with an errors[] at the end indicating not all items were processed. We have the onError param as well so the developer can get their desired behavior.

I've filed a separate issue on asking for a log() function.