You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@lucene.apache.org by "David Smiley (Commented) (JIRA)" <ji...@apache.org> on 2012/02/16 20:03:05 UTC
[jira] [Commented] (SOLR-2155) Geospatial search using geohash
prefixes
[ https://issues.apache.org/jira/browse/SOLR-2155?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13209613#comment-13209613 ]
David Smiley commented on SOLR-2155:
------------------------------------
If someone watching this issue has an interest in this capability winding its way into Solr out of the box, then I suggest you vote (and maybe "watch") LUCENE-3795. That issue is the first step, the subsequent step is a follow-on issue that will bring LSP's spatial-solr module which uses spatial-lucene (LUCENE-3795). I don't intend or support committing SOLR-2155 as is. Spatial done-right should involve a good framework; SOLR-2155 isn't a framework and Lucene's existing defunct spatial-contrib module isn't good. That's where LSP comes in, and LUCENE-3795 is the first step to get it incorporated into Lucene/Solr.
> Geospatial search using geohash prefixes
> ----------------------------------------
>
> Key: SOLR-2155
> URL: https://issues.apache.org/jira/browse/SOLR-2155
> Project: Solr
> Issue Type: Improvement
> Reporter: David Smiley
> Attachments: GeoHashPrefixFilter.patch, GeoHashPrefixFilter.patch, GeoHashPrefixFilter.patch, SOLR-2155_GeoHashPrefixFilter_with_sorting_no_poly.patch, SOLR.2155.p3.patch, SOLR.2155.p3tests.patch, Solr2155-1.0.2-project.zip, Solr2155-1.0.3-project.zip, 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 TermsEnum.seek() 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: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org