couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Seggy Umboh <seggy.um...@gmail.com>
Subject Re: Slow Map Reduce
Date Fri, 23 Oct 2009 01:10:03 GMT
It looks like you just want to find out how many rows were emitted? That
would just be the typical sum right?
return sum(values);



js> var v = 6
js> 0 + v.length
NaN



On Wed, Oct 21, 2009 at 11:45 PM, Rajkumar S <rajkumars@gmail.com> wrote:

> On Wed, Oct 21, 2009 at 9:48 PM, Paul Joseph Davis
> <paul.joseph.davis@gmail.com> wrote:
> > I suspect "return values;" is the culprit here. That's pretty much
> guranteed
> > to cause you problems as the data grows recursing up the tree. 0.10.0
> even
> > detects this and throws an error to avoid precisely this issue.
> >
> > It's been discussed a couple times on the list but my stomach is
> rumbling.
>
> That reduce function used in that log was the following.
>
> function(keys, values, rereduce)
> {
>    length = 0;
>    if (rereduce){
>        for(var v = 0; v < values.length; v++){
>            length = length + v.length;
>        }
>    } else {
>        length = values.length;
>    }
>    return length;
> }
>
> The reduce function should returns a single integer and not cause data
> to grow. Let me try with simpler map with no reduce and will report
> the results.
>
> with regards,
> raj
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message