lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Frederick N. Brier (Commented) (JIRA)" <>
Subject [jira] [Commented] (SOLR-2155) Geospatial search using geohash prefixes
Date Thu, 06 Oct 2011 10:40:30 GMT


Frederick N. Brier commented on SOLR-2155:

I am new to Solr/Solandra so it is not clear to me how to declare a POJO with the @Field annotation
for a GeoHashField. If I declare the property as a String, it seems to parse it and store
it (the below value is correct).  But the query response fails when it attempts to marshal
the GeoHashField data back into a String:

Exception while setting value : [32.76932462118566,-79.92890948429704] on java.lang.String
IllegalArgumentException: Can not set java.lang.String field mybuilding.latLong to java.util.ArrayList

Perhaps the property should be declared as a GeoHashField or a LatLonType to be properly marshaled
and unmarshaled, but with my unfamiliarity with Solr, I do not know how to store and retrieve
the value from those types in my getter/setter.  Thank you for any explanation on how to declare
the POJO.
> Geospatial search using geohash prefixes
> ----------------------------------------
>                 Key: SOLR-2155
>                 URL:
>             Project: Solr
>          Issue Type: Improvement
>            Reporter: David Smiley
>            Assignee: Grant Ingersoll
>         Attachments: GeoHashPrefixFilter.patch, GeoHashPrefixFilter.patch, GeoHashPrefixFilter.patch,
SOLR-2155_GeoHashPrefixFilter_with_sorting_no_poly.patch, SOLR.2155.p3.patch, SOLR.2155.p3tests.patch,,, Solr2155-for-1.0.2-3.x-port.patch
> There currently isn't a solution in Solr for doing geospatial filtering on documents
that have a variable number of points.  This scenario occurs when there is location extraction
(i.e. via a "gazateer") occurring on free text.  None, one, or many geospatial locations might
be extracted from any given document and users want to limit their search results to those
occurring in a user-specified area.
> I've implemented this by furthering the GeoHash based work in Lucene/Solr with a geohash
prefix based filter.  A geohash refers to a lat-lon box on the earth.  Each successive character
added further subdivides the box into a 4x8 (or 8x4 depending on the even/odd length of the
geohash) grid.  The first step in this scheme is figuring out which geohash grid squares cover
the user's search query.  I've added various extra methods to GeoHashUtils (and added tests)
to assist in this purpose.  The next step is an actual Lucene Filter, GeoHashPrefixFilter,
that uses these geohash prefixes in to skip to relevant grid squares in the
index.  Once a matching geohash grid is found, the points therein are compared against the
user's query to see if it matches.  I created an abstraction GeoShape extended by subclasses
named PointDistance... and CartesianBox.... to support different queried shapes so that the
filter need not care about these details.
> This work was presented at LuceneRevolution in Boston on October 8th.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:!default.jspa
For more information on JIRA, see:


To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message