Hi, If user wants to read a summary of a certain WFS feature type with a command like
ogrinfo -ro -so WFS:http://server.com/wfs ns:typeName GDAL seems to send then four separate commands: First: SERVICE=WFS&REQUEST=GetCapabilities&ACCEPTVERSIONS=1.1.0,1.0.0 Second: SERVICE=WFS&VERSION=1.1.0&REQUEST=DescribeFeatureType&TYPENAME=[list of all the typenames in the whole service] Third: SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=ns:typeName&RESULTTYPE=hits Fourth: SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&TYPENAME=ns:typeName Questions: - Why to send DescribeFeatureType for all the feature types when user is only interested in the named one "ns:typeName"? - Is is necessary to send the fourth request and read the whole layer from the service? I guess it is because GDAL wants to see the real geometries so it can calculate correct extents for the layer but it can be quite a heavy load for the WFS server. In fact the following line leads to an ultimate query "get everything that exists in the WFS service" orginfo -al -so WFS:http://server.com/wfs This will make one by one full GetFeatures for all the feature types in the whole service. My service has 55 feature types and many of them has more than million features and ogrinfo will probably fail if my server won't fail earlier with sending a few gigabytes of GML. I consider it a little bit dangerous that users can send such requests accidentally. I think that at least users should especially do something before GDAL would create the fourth request, the plain GetFeature. -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
