Thank you so much Stefan. Your reply is very helpful.
On Thu, Sep 1, 2016 at 4:09 PM, Stefan Klein <[email protected]> wrote: > Hi, > > 2016-09-01 12:22 GMT+02:00 Giridhar Addepalli <[email protected]>: > > > Hi, > > > > Function declaration for reduce functions look like > > > > function(keys, values, rereduce) { > > } > > > > My doubt is regarding the 'keys' parameter. > > Can multiple keys be passed to single invocation of custom reduce > function > > ? > > > > Yes. Each key corresponds to the value of the same index. > The keys could be same but could also differ if the view was queried with a > grouplevel. > > e.g. you have 3 documents, the view emits the keys: > [1,2,3] > [1,2,4] > [1,3,5] > > if you call the view with "group_level" = 1, reduce will be called once¹ > and keys² will be: > [ > [[1,2,3], documentid], > [[1,2,4], documentid], > [[1,3,5], documentid] > ] > > the result is assigned to "[1]" > > if you call the view with "group_level" = 2, reduce will be called twice¹ > and keys² will be: > [ > [[1,2,3], documentid], > [[1,2,4], documentid] > ] > > this result is assigned to "[1,2]" > > and > [ > [[1,3,5], documentid] > ] > > this result is assigned to "[1,3]" > > > Hope this helps, > Stefan > > > [1]: ignoring rereduce > [2]: CouchDB 1.6.1 here >
