incubator-couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Norman Barker <norman.bar...@gmail.com>
Subject Re: Multi-dimensional queries?
Date Tue, 09 Nov 2010 14:45:00 GMT
Hi Michael, Volker

I have been thinking for a while about hacking a ub-tree for couch,
http://en.wikipedia.org/wiki/UB-tree, but am concerned about the
patent issues, http://archives.postgresql.org/pgsql-general/2002-04/msg00349.php,
I know this was discussed a lot on the postgresql lists, wonder if
anyone here knows any more about it?

Norman

On Tue, Nov 9, 2010 at 2:28 AM, Volker Mische <volker.mische@gmail.com> wrote:
> Hi Michael,
>
> On 11/09/2010 07:14 AM, Michael Zedeler wrote:
>> Hi CouchDB-users (and developers).
>>
>> Thanks for a great product and very useful discussions on the mailing list.
>>
>> Does anyone know if there has been an effort into making
>> multi-dimensional queries possible?
>>
>> Given a d-dimensional keyspace, I'd like to be able to get all elements
>> in a d-dimensinal hypercube. It could be implemented using kd-trees.
>>
>> Any thoughts?
>>
>> Regards,
>>
>> Michael.
>>
>
> You could use an kd-tree, though I'd prefer a multidimensional variation
> of the r-tree. The reason is, that the kd-tree is space partitioning,
> which means you need to know the range the keys are in upfront (or do
> some tricks which will make it more like an r-tree).
>
> In an r-tree you partition the data, so your data structure grows as
> data from outside the current maximum range comes in.
>
> I'd love to see a multidimensional index, but atm I'm still busy with my
> 2-dimensional index. So if you'd like to hack on it and need any help,
> let me know.
>
> Cheers,
>  Volker
>

Mime
View raw message