On Tue, Apr 12, 2011 at 3:56 PM, Steve Coast <st...@asklater.com> wrote:
> Interesting. > > How efficient is the (big)int indexing and/or masking? > I haven't had a chance to look at the integer indexing/masking. If I remember it from discussions on dev a long while ago I think it's very close to geohashes. > > Was this all on a single machine? > Yes. > > > > > On 4/12/2011 1:52 PM, Ian Dees wrote: > > Yep. > > On Tue, Apr 12, 2011 at 3:51 PM, Steve Coast <st...@asklater.com> wrote: > >> and using the builtin spatial index? >> >> >> >> On 4/12/2011 1:50 PM, Ian Dees wrote: >> >> Yes, one document per node/way/relation. >> >> On Tue, Apr 12, 2011 at 3:47 PM, Steve Coast <st...@asklater.com> wrote: >> >>> how was the data put in the db though? 1 document per node? >>> >>> >>> On 4/12/2011 1:39 PM, Nolan Darilek wrote: >>> >>> Oopse, meant for this to go to the whole list. >>> >>> >>> >>> -------- Original Message -------- Subject: Re: [OSM-dev] OSM and >>> MongoDB Date: Tue, 12 Apr 2011 15:26:41 -0500 From: Nolan Darilek >>> <no...@thewordnerd.info> <no...@thewordnerd.info> To: Ian Dees >>> <ian.d...@gmail.com> <ian.d...@gmail.com> >>> >>> I had/am having a somewhat bad experience storing OSM data in MongoDB. >>> >>> Initially I stored all map data in MongoDB, but queries took ages. The >>> same queries that happen in 100-200 MS now often took nearly a second. >>> Additionally, some took upwards of 5, and I even found spots on my map >>> sparsely populated with points, but which reliably performed the queries I >>> need in 30+ seconds. >>> >>> I filed a thorough bug in their tracker, including a dataset and queries >>> that reliably duplicated the issue. It was marked wontfix, I abandoned >>> MongoDB, and it was apparently re-opened and fixed several months later. So >>> perhaps it's a non-issue now. >>> >>> I'm still using MongoDB for part of my current project, user POI storage. >>> It does indeed use geohashes, and I'm experiencing strange accuracy issues. >>> My platform is pedestrian navigation with many small distance queries. >>> Points in the non-MongoDB dataset are reliably detected in a radius roughly >>> 100 meters around the traveler. Points in MongoDB queried with the same >>> bounding boxes don't appear until they're within 30-40 meters. I recently >>> updated from an older version to a new build of 1.8. The older version >>> widely varied the detection range. Some points were detected 100 or so >>> meters out, while others weren't picked up until 30 or so. It was always the >>> same points, too. The point for my apartment remains reliably visible for >>> ~100 meters or so, while the corner store and restaurant didn't appear until >>> I was very close. 1.8 at least appears to be consistent, always detecting at >>> 30 meters or so. I can only assume that this is a geohash oddity that only >>> appears for very small differences, something that works out to rounding >>> error for larger values. >>> >>> I like MongoDB for many things, but not for geospatial data more >>> complicated than a series of points. I'm working on migrating user/POI >>> storage to a geospatial store. >>> >>> >>> On 04/12/2011 01:20 PM, Ian Dees wrote: >>> >>> Yep, and I think Mongo uses geohashes as their index behind the scenes. >>> One of the problems with that, though, is they have some arbitrary length >>> that they compute the geohash to and when you have lots of points (as OSM >>> data does) the buckets they're searching are very full. >>> >>> On Tue, Apr 12, 2011 at 1:00 PM, Steve Coast <st...@asklater.com> wrote: >>> >>>> bbox queries using the built in spatial indexing presumably? OSM has >>>> it's own magical bitmask for that, that may also be as fast in mongo, who >>>> knows. >>>> >>>> >>>> On 4/11/2011 5:58 PM, Ian Dees wrote: >>>> >>>> On Mon, Apr 11, 2011 at 6:36 PM, Sergey Galuzo >>>> <ser...@microsoft.com>wrote: >>>> >>>>> Hi, >>>>> >>>>> >>>>> >>>>> I am working on evaluation of MongoDB for several storage solutions at >>>>> hand. Some of them resemble current OSM editing database. I have heard >>>>> that >>>>> OSM dev is/was evaluating MongoDB also. I was wondering whether it >>>>> possible >>>>> to share the findings? >>>>> >>>>> >>>>> >>>> >>>> In my experimentation with MongoDB (seen here: >>>> https://github.com/iandees/mongosm/) I found it to be very slow. >>>> Inserts were speedy, but bounding-box queries took a long time. >>>> >>>> The most recent dev version of MongoDB includes "multi-location >>>> documents" support: >>>> >>>> http://www.mongodb.org/display/DOCS/Geospatial+Indexing#GeospatialIndexing-MultilocationDocuments >>>> >>>> This would allow a single way document to be indexed at multiple >>>> locations and vastly speed up the map query. >>>> >>>> >>>> _______________________________________________ >>>> dev mailing list >>>> dev@openstreetmap.orghttp://lists.openstreetmap.org/listinfo/dev >>>> >>>> >>>> _______________________________________________ >>>> dev mailing list >>>> dev@openstreetmap.org >>>> http://lists.openstreetmap.org/listinfo/dev >>>> >>>> >>> >>> _______________________________________________ >>> dev mailing >>> listdev@openstreetmap.orghttp://lists.openstreetmap.org/listinfo/dev >>> >>> >>> >>> _______________________________________________ >>> dev mailing >>> listdev@openstreetmap.orghttp://lists.openstreetmap.org/listinfo/dev >>> >>> >>> _______________________________________________ >>> dev mailing list >>> dev@openstreetmap.org >>> http://lists.openstreetmap.org/listinfo/dev >>> >>> >> >
_______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
