[google-appengine] Re: fast bounding-box geo queries?
On Oct 5, 9:48 pm, Josh Haberman wrote: > I was looking at GeoModel, which has nice functionality for bounding- > box geo > queries:http://code.google.com/apis/maps/articles/geospatial.htmlhttp://code.google.com/p/geomodel/ > > Unfortunately, the demo application is quite slow. Queries often take > 2-4 seconds to return ~10 > results.http://geomodel-demo.appspot.comhttp://geomodel-demo.appspot.com/speedtest > > I also see an open bug filed against GeoModel that proximity queries > are slow:http://code.google.com/p/geomodel/issues/detail?id=20 > > Any ideas why this is slow? Glancing at the source, I notice it uses > "IN" queries (eg. location_geocells IN ) -- perhaps > this is less efficient than range queries? But still, 2-4 seconds > seems excessive to return 10 results. > > Hopefully the "next gen queries" which will apparently support space- > filling curves will provide better performance for queries like > these?http://www.youtube.com/watch?v=ofhEyDBpngM > > Josh Why is it slow? I use it and yes it's slow since making several queries for one match. You could try do it with your own algorithm. I try match points inside a polygon for arbitrary geography matches. When slow we usually have 2 alternatives a) faster platform b) make fewer calls and fewer objects You may benchmark my code matching stuff in Sao Paulo by long / lat: http://www.montao.com.br/li?lat=-23.33&lon=-46.38 Sincerely, Niklas -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
[google-appengine] Re: fast bounding-box geo queries?
Hi Josh, The GeoModel bounding-box performance depends on the "zoom level" the query is running. As the box get smaller in size (closer bound coordinates) the performance is better, this is because you query on less squares (see Geohash http://en.wikipedia.org/wiki/Geohash for more info) It also depends on if you are using a sub-query, doing more data fetching and more... The best thing is to make a mock-up for your needs, and see if it's right for you. Happy geo-coding On Oct 5, 11:48 pm, Josh Haberman wrote: > I was looking at GeoModel, which has nice functionality for bounding- > box geo > queries:http://code.google.com/apis/maps/articles/geospatial.htmlhttp://code.google.com/p/geomodel/ > > Unfortunately, the demo application is quite slow. Queries often take > 2-4 seconds to return ~10 > results.http://geomodel-demo.appspot.comhttp://geomodel-demo.appspot.com/speedtest > > I also see an open bug filed against GeoModel that proximity queries > are slow:http://code.google.com/p/geomodel/issues/detail?id=20 > > Any ideas why this is slow? Glancing at the source, I notice it uses > "IN" queries (eg. location_geocells IN ) -- perhaps > this is less efficient than range queries? But still, 2-4 seconds > seems excessive to return 10 results. > > Hopefully the "next gen queries" which will apparently support space- > filling curves will provide better performance for queries like > these?http://www.youtube.com/watch?v=ofhEyDBpngM > > Josh -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
