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Check out this code for searching locally with mongo. It doesn't get simpler. Straight from geosay.com class GeosayController < ApplicationController def ap

Check out this code for searching locally with mongo. It doesn't get simpler. Straight from geosay.com class GeosayController < ApplicationController def api expires_in 1.minutes, :public => true results = Tweet.near(params[:lat].to_f,params[:lon].to_f) render :json => results end end .... class Tweet include MongoMapper::Document def self.near(lat, lon) self.all( :latlong => {'$near' => [lat, lon]}, :limit => 30) end end

stewsnooze 16y ago
We chose mongodb after reading this page http://www.mongodb.org/display/DOCS/Geospatial+Indexing http://www.mongodb.org/display/DOCS/Geospatial+Indexing Before then we were looking at Postgres for its geo stuff and things like cassandra also.
- djb_hackernews 16y ago
  as someone building a location based service, why not just store the lat/long in a table column and query for < >? Is it that much more efficient to use a specialized product?
  - dansingerman 16y ago
    Our understanding is mongodb should scale to tens of millions of rows better than a SQL database (which would be a nice problem to have) Once we made the decision to use mongodb, it made sense to use the built in near functionality, rather than roll it ourselves.
    - djb_hackernews 16y ago
      Indeed. I am using Django to build my app and a mysql db with 2 float fields for lat/long. GeoDjango and GIS extensions for mysql seemed like over kill, plus I don't really know what I am doing but it seems to work. Django doesn't have very good support for mongo. Well, the django orm.
      - dansingerman 16y ago
        To be honest I can see absolutely no reason why you can't use floats as you describe and < , >. Depending on what you are doing it may be a little tricky due to lat/longs being angular values, but over small distances I think this can be largely ignored. (In geosay we have some front end code that sorts out the niceties of the angular stuff)

stewsnooze 16y ago

We chose mongodb after reading this page http://www.mongodb.org/display/DOCS/Geospatial+Indexing http://www.mongodb.org/display/DOCS/Geospatial+Indexing Before then we were looking at Postgres for its geo stuff and things like cassandra also.

djb_hackernews 16y ago
as someone building a location based service, why not just store the lat/long in a table column and query for < >? Is it that much more efficient to use a specialized product?
- dansingerman 16y ago
  Our understanding is mongodb should scale to tens of millions of rows better than a SQL database (which would be a nice problem to have) Once we made the decision to use mongodb, it made sense to use the built in near functionality, rather than roll it ourselves.
  - djb_hackernews 16y ago
    Indeed. I am using Django to build my app and a mysql db with 2 float fields for lat/long. GeoDjango and GIS extensions for mysql seemed like over kill, plus I don't really know what I am doing but it seems to work. Django doesn't have very good support for mongo. Well, the django orm.
    - dansingerman 16y ago
      To be honest I can see absolutely no reason why you can't use floats as you describe and < , >. Depending on what you are doing it may be a little tricky due to lat/longs being angular values, but over small distances I think this can be largely ignored. (In geosay we have some front end code that sorts out the niceties of the angular stuff)