You can use the second with group_level=1 and get all the groups at the
same time.
And you can use _count instead of _sum, so you don't even need to emit any
value, just the key.
On Sat, Oct 4, 2014 at 8:24 PM, Boaz Citrin <bcit...@gmail.com> wrote:
> Hello,
>
> My documents contain two fields to maintain group associations, say "group"
> holds the group document id, and "associated" holds the date this document
> was added to the group.
> Now I want to be able to know how many documents were added to a given
> group[s] between two given dates.
> The challenge is that to be able to filter by dates, I need to have the
> date as the key first part.
> But I also need the group as the first key part in order to aggregate the
> number of group associations.
>
> So I see two options here:
>
> 1.
> Map: associated, {"group": group}
> Reduce: a function that aggregates all values by group, which I assume is
> fine as I know the number of groups is relatively small.
> (plus configuring reduce_limit=false ...)
>
> 2.
> Map: [group,associated], 1
> Reduce: sum(values)
> Here I cannot retrieve multiple groups at once, so I use a request per
> desired group.
>
> Tried the two approaches, with the first one gives faster response. Which
> leads me to two questions:
> 1. Is there any risk in a reduce function that produces a potentially long
> string?
> 2. Is there a better way to achieve what I do here?
>
> Thanks!
>
> Boaz
>
