Geolocation in mongodb
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This document discusses geolocation features in MongoDB. It describes how to store location data in MongoDB documents using latitude and longitude coordinates. It also covers geospatial indexing, queries like $near, $within, and $geoNear to find or count documents within certain locations, distances, and shapes. Precision and performance of different geospatial queries and indexes are also compared.
![MONGO DOC WITH LOC
{ loc : [37.407202, -122.10716] }
{ loc : { x: 37.407202, y: -122.10716} }
{ loc : { lat: 37.407202, lon: -122.10716} }
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-6-320.jpg)
![EXACT QUERIES
> db.places.find({ loc : [ 37.407202, -122.10716 ]});
{ "_id" : ObjectId("50b69e66e6945f62a019f3a4"), "name" :
"San Antonio Caltrain", "loc" : [ 37.407202, -122.10716 ] }
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-10-320.jpg)
![EXPLAIN QUERY PLAN
db.places.find({ loc : [ 37.407202, -122.10716 ]}).explain();
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-11-320.jpg)
![NEAR QUERY
db.places.find({ loc : { $near : [ 37.407202, -122.10716 ]}});
Returns points sorted by distance
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-13-320.jpg)
![WITH MAXDISTANCE
db.places.find({ loc : { $near : [ 37.407202, -122.10716 ],
$maxDistance : 0.05}});
What is the unit of maxDistance? -- for latitude & longitude 1
degree ~ 69 miles
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-14-320.jpg)
![GEONEAR QUERY
db.runCommand({ geoNear : "places", near : [37.407202,
-122.10716], num : 5 });
also gives the distance
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-15-320.jpg)
![MORE WITH GEONEAR
db.runCommand({ geoNear : "places", near : [37.407202,
-122.10716], num : 5, type : “DO” });
parameters: near, num, maxDistance, query
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-16-320.jpg)
![WITHIN A BOX
db.places.find({ loc : { $within : { $box : [[39.589821,
-122.438831], [37.485200, -122.228438]] }}});
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-17-320.jpg)
![WITHIN A CIRCLE
db.places.find({ loc : { $within : { $center : [[39.589821,
-122.438831], 10] }}});
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-18-320.jpg)
![MULTI LOCATIONS
db.places.insert({ placesVisitedToday : [ { name : "San
Antonio Caltrain", loc : [37.407202, -122.10716] }, { name :
"Kixeye", loc : [37.7906672, -122.403256] } ] })
Wednesday, November 28, 12](https://image.slidesharecdn.com/geolocationinmongodb-121130120024-phpapp01/85/Geolocation-in-mongodb-21-320.jpg)
Geolocation in mongodb
- 1. GEOLOCATION IN MONGODB { name: ‘Shashank Tiwari’, web: ‘shanky.org’} Wednesday, November 28, 12
- 2. WHO AM I? Entrepreneur, developer, author Most recent book: Professional NoSQL (Wiley, 2011) Co-founder : Wednesday, November 28, 12
- 3. DEGREES OF MEASURE Latitude Longitude Wednesday, November 28, 12
- 4. DEGREE OF LONGITUDE Wednesday, November 28, 12
- 5. GEO IN MONGO Is a world in 2D Wednesday, November 28, 12
- 6. MONGO DOC WITH LOC { loc : [37.407202, -122.10716] } { loc : { x: 37.407202, y: -122.10716} } { loc : { lat: 37.407202, lon: -122.10716} } Wednesday, November 28, 12
- 7. INDEX db.places.ensureIndex( { loc : "2d" } ) 1 geospatial index per collection Wednesday, November 28, 12
- 8. INDEX RANGE db.places.ensureIndex( { loc : "2d" } , { min : -500 , max : 500 } ) Wednesday, November 28, 12
- 9. INDEX PRECISION db.places.ensureIndex( { loc : "2d" } , { bits : 26 } ) Geo-hash precision of 26bits ~ 2 feet Wednesday, November 28, 12
- 10. EXACT QUERIES > db.places.find({ loc : [ 37.407202, -122.10716 ]}); { "_id" : ObjectId("50b69e66e6945f62a019f3a4"), "name" : "San Antonio Caltrain", "loc" : [ 37.407202, -122.10716 ] } Wednesday, November 28, 12
- 11. EXPLAIN QUERY PLAN db.places.find({ loc : [ 37.407202, -122.10716 ]}).explain(); Wednesday, November 28, 12
- 12. COMPOUND INDEX db.places.ensureIndex( { loc : "2d", name : 1 } ) Wednesday, November 28, 12
- 13. NEAR QUERY db.places.find({ loc : { $near : [ 37.407202, -122.10716 ]}}); Returns points sorted by distance Wednesday, November 28, 12
- 14. WITH MAXDISTANCE db.places.find({ loc : { $near : [ 37.407202, -122.10716 ], $maxDistance : 0.05}}); What is the unit of maxDistance? -- for latitude & longitude 1 degree ~ 69 miles Wednesday, November 28, 12
- 15. GEONEAR QUERY db.runCommand({ geoNear : "places", near : [37.407202, -122.10716], num : 5 }); also gives the distance Wednesday, November 28, 12
- 16. MORE WITH GEONEAR db.runCommand({ geoNear : "places", near : [37.407202, -122.10716], num : 5, type : “DO” }); parameters: near, num, maxDistance, query Wednesday, November 28, 12
- 17. WITHIN A BOX db.places.find({ loc : { $within : { $box : [[39.589821, -122.438831], [37.485200, -122.228438]] }}}); Wednesday, November 28, 12
- 18. WITHIN A CIRCLE db.places.find({ loc : { $within : { $center : [[39.589821, -122.438831], 10] }}}); Wednesday, November 28, 12
- 19. WITHIN A POLYGON Polygon shapes currently cannot be indexed Wednesday, November 28, 12
- 20. SPHERICAL SUPPORT geoNear -- spherical : true $nearSphere $centerSphere Order is important, very important -- longitude, latitude Wednesday, November 28, 12
- 21. MULTI LOCATIONS db.places.insert({ placesVisitedToday : [ { name : "San Antonio Caltrain", loc : [37.407202, -122.10716] }, { name : "Kixeye", loc : [37.7906672, -122.403256] } ] }) Wednesday, November 28, 12
- 22. QUERY MULTI LOC db.places.ensureIndex( { " placesVisitedToday.loc " : "2d"} ) use uniqueDocs : true to get unique documents Wednesday, November 28, 12
- 23. Wednesday, November 28, 12
- 24. Wednesday, November 28, 12
- 25. NEXT TALK More details and some about GIS too! SV MongoDB User Group @ Palo Alto -- January Meetup Wednesday, November 28, 12
- 26. THANKS More questions? web: shanky.org | twitter : @tshanky Want to join the alpha program? doaround.com Wednesday, November 28, 12