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David Smiley commented on SOLR-2155: ------------------------------------ Lance, sorry, you've completely lost me; I don't understand anything you've said. Can you please try to explain your points in more detail, any of them at least? I don't see what's so special about this point on the earth you've drawn attention to: 65°37′21″N 168°20′42″W geohash: b7b01fqvuff1 No point or location in geohash is special or problematic. There are gridlines at every resolution which need to be dealt with -- and it's not hard. > 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 > > > 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. - You can reply to this email to add a comment to the issue online. --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org