[postgis-users] How to design a database for continents, countries, regions, cities and POIs?

[Andrea Peri]

>Thank's for your reply.
>
>I think we'll go same ways as you describe - use two main tables `polygons`
>and `points` and couple supporting tables which handle relationships
>and additional content.
>
>Michal K.


Hi,
If you plan to use two tables of kind polygons and point, and don't plan to
use an explicit line table,
I guess you should use the new postgis topology feature.

You should create a topology (node,edge,face) and apply a TopoGeometry over
that topology.
Where the topogeometry should be the "polygons" you will use in your main
table.

This approach is really important because otherwise the polygons you will
use in the main table don't be really topology to each-other.

Please don't understimate the important of postgis topology.
Expecially when you plan to describe temathics informations like city
boundaries, countries and so on.
The simple relationships between polygons is not sufficient to grant a
really exact separation between two countries :)
When we don't use topology we found often some little area where there is
two or more cities :)

-- 
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Andrea Peri
. . . . . . . . .
qwerty àèìòù
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