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Re: Spatial data posting in HBase
Michael, don't you think Geohashes can be satisfying and well-suited for
many cases anyway? Searching in a bounding box or arbitrary polygon is not
that heavy with Geohash, even on edge conditions. The biggest risk IMHO is
to have to deal with tons of invalid extra points if the geohash query is
not accurate enough and your points distribution is very sparse so that
many points will be found in a geohash despite they don't respond to your
query criteria.

However, if your query embeds enough bits of precision, Geohashes offer
some nice guarantees for distributed databases and your queries should
remain efficient enough.

Another worst case of course is to look for K-NN since Geohash is not a
real longest-common-prefix algorithm but once again, if your points
distribution is approximately well balanced, this works not that bad
without doing lots of recursive queries or fetching tons of useless data
(but I do agree looking into your tiles would probably be more appropriate
in that case).

I'm planning to write an article on that points, so further technical
arguments are welcome :-}

On Thu, Oct 10, 2013 at 7:51 PM, Michael Segel <[EMAIL PROTECTED]>wrote:

> HBase in Action goes through great depth of showing you how you could
> implement GIS information in HBase.
>
> Unfortunately there are issues with Geohash and edge conditions which make
> it difficult to use when you're dealing with data on an edge of a quadrant.
>
> A better way would be to create a point (geospatial point object) and
> store it in a single column.
> (This goes beyond the example of what's in the book. ) And then index the
> data by tiles.
>
>
> The downside is that you end up creating a lot more data…
>
> Take a look at some of the stuff Boris Lublinsky published on InfoQ. There
> are also other articles on the net….
>
> On Oct 9, 2013, at 1:35 PM, Otis Gospodnetic <[EMAIL PROTECTED]>
> wrote:
>
> > The point is that there are options (multiple different hammers) if
> > HBase support for geospatial is not there or doesn't meet OP's needs.
> >
> > Otis
> > --
> > Solr & ElasticSearch Support -- http://sematext.com/
> > Performance Monitoring -- http://sematext.com/spm
> >
> >
> >
> > On Wed, Oct 9, 2013 at 11:14 AM, Michael Segel
> > <[EMAIL PROTECTED]> wrote:
> >> And Solr has what to do with storing data in HBase?
> >>
> >> I guess its true… if all you have is a hammer…
> >>
> >> The point I was raising was that geohash isn't the most efficient way
> to go when you look at the problem at a global level…
> >>
> >> On Oct 9, 2013, at 9:34 AM, Otis Gospodnetic <
> [EMAIL PROTECTED]> wrote:
> >>
> >>> Consider using Solr, which provides a lot of geospatial search support.
> >>>
> >>> Otis
> >>> Solr & ElasticSearch Support
> >>> http://sematext.com/
> >>> On Sep 24, 2013 8:29 AM, "cto" <[EMAIL PROTECTED]> wrote:
> >>>
> >>>> Hi ,
> >>>>
> >>>> I am very new in HBase. Could you please let me know , how to insert
> >>>> spatial
> >>>> data (Latitude / Longitude) in HBase using Java .
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> View this message in context:
> >>>>
> http://apache-hbase.679495.n3.nabble.com/Spatial-data-posting-in-HBase-tp4051123.html
> >>>> Sent from the HBase User mailing list archive at Nabble.com.
> >>>>
> >>
> >
>
>
--
Adrien Mogenet
http://www.borntosegfault.com