[mapserver-users] Mapserver doesn't send good filter to postgis

[Lime, Steve D (MNIT)]

MapServer does use the supplied geometry, it's a matter of where the filter is applied - the database or in MapServer. This isn't a new limitation so others may have more experience with workarounds. Maybe try also setting a bbox in the filter based on the bbox of the geometry?

Steve

From: Steve.Toutant at inspq.qc.ca [mailto:Steve.Toutant at inspq.qc.ca]
Sent: Monday, January 26, 2015 9:38 AM
To: Lime, Steve D (MNIT)
Cc: mapserver-users at lists.osgeo.org
Subject: RE: [mapserver-users] Mapserver doesn't send good filter to postgis


I understand the objective of rfc 91, but the most common use case would be to pass the supplied geometry.....

If mapserver doesn't use the supplied geometry, that means that it doesn't support spatial filtering.

Our data covers the whole country, not using the supplied geometry means we can't use mapserver as a wfs server....

Is there something we can do about it? A workaround we could use?


"Lime, Steve D (MNIT)" <Steve.Lime at state.mn.us<mailto:Steve.Lime at state.mn.us>>

2015-01-26 10:14

A

"Steve.Toutant at inspq.qc.ca<mailto:Steve.Toutant at inspq.qc.ca>" <Steve.Toutant at inspq.qc.ca<mailto:Steve.Toutant at inspq.qc.ca>>, "mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>" <mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>>

cc

Objet

RE: [mapserver-users] Mapserver doesn't send good filter to postgis









It's a limitation in older versions of MapServer where specific backend optimizations were scattered about the WMS/WFS code. Most of those optimizations address the most common use cases - I guess this wasn't one of them. It's surprising that at worst the extent of the supplied geometry isn't passed (I see a comment in the WFS code about this). The specific filter intersection test is applied on the MapServer side - the results are correct, performance can suffer though.

This is being addresses in MapServer 7.0 where more complete filter translation functions are being supported (RFC 91).

Steve

From: mapserver-users-bounces at lists.osgeo.org<mailto:mapserver-users-bounces at lists.osgeo.org> [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of Steve.Toutant at inspq.qc.ca<mailto:Steve.Toutant at inspq.qc.ca>
Sent: Monday, January 26, 2015 8:55 AM
To: mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org>
Subject: [mapserver-users] Mapserver doesn't send good filter to postgis

Sorry my first post was with an inapprpriate title......

I'm using mapserver 6.4.1 and postgis 2.1

using OpenLayers 2.13.1 I draw a small polygon that I use for a within spatial filter of a WFS getfeature request. The problem is that mapserver is not sending this polygon to postgis, it is sending the extent of the mapfile as filter...

The wfs POST Request (created and send by OpenLayers client)
<ogc:Filter xmlns:ogc="http://www.opengis.net/ogc"><ogc:Within><ogc:PropertyName>msGeometry</ogc:PropertyName><gml:Polygon xmlns:gml="http://www.opengis.net/gml" srsName="urn:ogc:def:crs:EPSG::3857"><gml:exterior><gml:LinearRing><gml:posList>-8081644.2511244 5835062.56996 -8081707.5505384 5834980.1612889 -8081638.2794815 5834913.2788892 -8081533.1785677 5834988.5215889 -8081644.2511244 5835062.56996</gml:posList></gml:LinearRing></gml:exterior></gml:Polygon></ogc:Within></ogc:Filter>

In Mapserver log, I see
FLTLayerApplyPlainFilterToLayer():  ([shape]  within  fromText('POLYGON ((-8081644.2511243997141719 5835062.5699599999934435, -8081707.5505384001880884 5834980.1612889003008604, -8081638.2794815003871918 5834913.2788891997188330, -8081533.1785677000880241 5834988.5215889001265168, -8081644.2511243997141719 5835062.5699599999934435))'))

Then a few lines later, I see that it is not sending the polygon received as filter
select .......  where geom_p && ST_GeomFromText('POLYGON((-9239517 5465442,-9239517 9349764,-5565974 9349764,-5565974 5465442,-9239517 5465442))',3857);

See the polygon definition is different, postgis receive the extent defined in the mapfile
EXTENT -9239517 5465442 -5565974 9349764


And, in postgis log I see this query, See the
select ....... where geom_p && ST_GeomFromText('POLYGON((-9239517 5465442,-9239517 9349764,-5565974 9349764,-5565974 5465442,-9239517 5465442))',3857);


Why Mapserver is not sending the polygon received as filter to postgis?


Thanks!

Steve Toutant, M. Sc.
Analyste en géomatique
Secteur environnement
Direction de la santé environnementale et de la toxicologie
Institut national de santé publique du Québec
Tél.: 418 646-6777 poste 30015
Téléc.: 418 644-4593
steve.toutant at inspq.qc.ca<mailto:steve.toutant at inspq.qc.ca>
http://www.inspq.qc.ca<http://www.inspq.qc.ca/>
http://www.monclimatmasante.qc.ca<http://www.monclimatmasante.qc.ca/>

Pour me rejoindre par courrier
Service de l'infrastructure et du réseau
Direction des technologies de l'information
Ministère de la Sécurité Publique
2525 boul. Laurier, 2e étage
Tour Laurentides
Québec, G1V 2L2

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