Reducing information

[Bart van den Eijnden]

Hi,

I think your approach is right.

PostGIS has a function called Simplify which could simplify geometries, use that function to create a new simplified table.

Simplify(geometry, tolerance)

    Returns a "simplified" version of the given geometry using the Douglas-Peuker algorithm. Will actually do something only with (multi)lines and (multi)polygons but you can safely call it with any kind of geometry. Since simplification occurs on a object-by-object basis you can also feed a GeometryCollection to this function. Note that returned geometry might loose its simplicity (see IsSimple)

Best regards,
Bart

Bart van den Eijnden
Syncera IT Solutions
Postbus 270
2600 AG  DELFT

tel.nr.: 015-7512436
email: BEN at Syncera-ITSolutions.nl
>>> José Vte Higón <higon_jos at GVA.ES> 10/05/05 9:24 AM >>>
Hi list,
I have running mapserver with postgis and I want to serve a huge layer which
original datasource is a shapefile with 1Gb size. If I try to get the layer
with a full extent the request take long time to be visualized. In order to
solve my problem, I have configured two layers, the first one can be
visualized when the scale it's very small and the datasource is the original
shapefile into postgis, the other one only can be visualized when the scale
is bigger but I need a datasource smaller than the original. Finally I have
a unique layer accesing both with a wms connection type (as wms client).

How can I get a datasource smaller than the original shapefile (or postgis
table)?
Is my solution the correct approach to the problem?

Thanks in advance.