[postgis-devel] Geodetic Plan

nicklas.aven at jordogskog.no nicklas.aven at jordogskog.no
Thu Jun 18 23:43:18 PDT 2009


Hallo I have a thought about indexing. Idon't know much about them but I have read some headings from the diskussions about deviding features to get more out of the geometries. I guess the issues about comparing big to small will be more common when handling "the whole world".Wouldn't it be possible to just devide the index.  The bounding-boxes would be just like the divided features bboxes but just be indexes. I think one example to discuss this from is a query asking for all towns close to the atlantic oscean. With a boundingbox to the atlantic the index will give us most of the towns in the world.  The idea is to build the index like, lets say, for example one bounding box to the representation of the atlantic in each long/lat degree.Then the index could fist scan all towns sharing "lat/long-degree boxes" with the atlantic from some static ID of the boxes, then select from them using the smaller boundingboxes to the atlantic.  Or maybe it would be better to divide the ind!
 exes in relation to the size of the object. I don't know I say like Regina:Crazy thought so feel free to knock it down.
or maybe it's alreagy out there.
 /Nicklas 
2009-06-18 Paul Ramsey wrote:

Folks,
>
>I may be getting a contract to bring in geodetic support in the next
>little while. The challenge is to bring in this potentially big piece
>of new functionality, and have it into a released version in around 9
>months. I have been thinking about different ways to approach the
>implementation and placed some thoughts here.
>
>http://files.getdropbox.com/u/1184727/geodetic-plan.txt
>
>I'm interested to hear your thoughts about what the most useful
>approach would be. The client wants to see this work in the core
>distribution, and OpenGeo has an interest in the longer term vision of
>PostGIS, so the most expedient approach is not necessarily required,
>we can choose something that balances our long-term vision with the
>short-term need to have working code in a numbered release.
>
>Yours,
>
>Paul
>_______________________________________________
>postgis-devel mailing list
>postgis-devel at postgis.refractions.net
>http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
>
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