couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Chris Anderson" <jch...@gmail.com>
Subject Re: slow views
Date Sun, 21 Dec 2008 08:12:31 GMT
On Sat, Dec 20, 2008 at 8:50 PM, Antony Blakey <antony.blakey@gmail.com> wrote:
>
> On 21/12/2008, at 3:15 PM, Paul Davis wrote:
>
>> On Sat, Dec 20, 2008 at 11:32 PM, Antony Blakey <antony.blakey@gmail.com>
>> wrote:
>>>
>>> On 21/12/2008, at 2:54 PM, Paul Davis wrote:
>>>
>>>> View update times should be linear in terms of *new* records.
>>>
>>> Well, with a factor to deal with the reduction, which isn't O(n).
>>>
>>
>> Kinda. I'm pretty sure they're still O(N), just not as pre calculated
>> as one might expect.
>
> I would have thought + a tiny O(log M) where M is determined by the grouping
> size of the partial reductions.

I think there's at least a linear cost associated with the number of
groups in the final reduction. eg. a group=true result requires N as
many as there are unique keys. If your range encompasses 5 groups,
then you'd require 5 final reductions to be run. Requesting the same
range with group=false, I'd expect a substantial speedup.

If it's less than a linear relation to the number of groups, I'd be happy.

-- 
Chris Anderson
http://jchris.mfdz.com

Mime
View raw message