[Geoserver-users] Location filter

GeoServer GeoServer User
1

For all kind of services....

I have create areas of interrest with the bounding box.... but I don't know if it's the best way....
The SLD contains more than 30 differents rules and the rendering for WFS take a bit of time.... How can I increase the rendering speed?? with better filters??

wkr,

Simon

-----Original Message-----
From: Andrea Aime [mailto:aaime@anonymised.com]
Sent: woensdag 22 april 2009 17:51
To: Simon Janssens
Cc: geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Location filter

Simon Janssens ha scritto:

Hi all,

is it possible to create a location filter?

I have data for the whole world, but i would like to create one service
for the America, one for the Europe, one for the Asia....

I store my data into a MySQL database and I can only use the coordinates
if I want to know the location of a record....

Any idea??

A location filter for... what? WMS, WFS? And location how, point
intersection, polygon containment,...?
It's possible for both, but for WFS there is a native syntax,
whilst WMS does not have that natively, but we added a vendor parameter
to support custom filtering.

Cheers
Andrea

--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.

2

Simon Janssens ha scritto:

For all kind of services....

The following filter works with both SLD and WFS requests:

<ogc:Filter>
       <ogc:BBOX>
         <ogc:PropertyName>the_geom</ogc:PropertyName>
         <gml:Box srsName="http://www.opengis.net/gml/srs/epsg.xml#4326&quot;&gt;
            <gml:coordinates>-75.102613,40.212597 -72.361859,41.512517</gml:coordinates>
         </gml:Box>
       </ogc:BBOX>

To see more kinds of spatial filters read the Filter 1.0 and GML 2 specifications you can download at http://www.opengeospatial.org/

I have create areas of interrest with the bounding box.... but I
don't know if it's the best way.... The SLD contains more than 30
differents rules and the rendering for WFS take a bit of time.... How
can I increase the rendering speed?? with better filters??

You mean WMS I guess (WFS does not use SLD).
Speed wise, it depends a lot on your data source.
One thing is that filtering in SLD is ignored if you
have too many rules, basically because some databases would choke
if we send a too big SQL query (to make just one query we have
to put in or all the filter you specified in your rules).
The current limit is 20 conditions, and it's hard coded.

One thing you can do is to add an external filter in the
request, something like:
...&request=GetMap&...&CQL_FILTER=BBOX(the_geom,-100,33,-99,34)

(full CQL BNF available here:
http://geotools.codehaus.org/CQL+Parser+Design)

Cheers
Andrea

--
Andrea Aime
OpenGeo - http://opengeo.org
GeoServer optimization and fine tuning