Can QGIS read layers in OGR's virtual vector format? It seems to work with VRT raster files, but it reports my layer is an invalid data source for vectors.
http://www.gdal.org/drv_vrt.html
I'm running QGIS 2.6 on Windows with GDAL 1.11.0 (which supports virtual vectors).
I've created a virtual layer as follows, which concatenates 4 shapefile layers.
The reason for wanting to do this is that the data is too big to fit into a single shapefile. I could use another format, but it would be more convenient if I could just use a virtual raster. I'm sure there a plenty of valid reasons for wanting to do this.
<OGRVRTDataSource>
<OGRVRTUnionLayer name="unionLayer">
<OGRVRTLayer name="OSMM_SPNE">
<SrcDataSource>OSMM_SPNE.shp</SrcDataSource>
</OGRVRTLayer>
<OGRVRTLayer name="OSMM_SPNW">
<SrcDataSource>OSMM_SPNW.shp</SrcDataSource>
</OGRVRTLayer>
<OGRVRTLayer name="OSMM_SPSE">
<SrcDataSource>OSMM_SPSE.shp</SrcDataSource>
</OGRVRTLayer>
<OGRVRTLayer name="OSMM_SPSW">
<SrcDataSource>OSMM_SPSW.shp</SrcDataSource>
</OGRVRTLayer>
</OGRVRTUnionLayer>
</OGRVRTDataSource>
The ogrinfo
tool can read the layer correctly:
$ ogrinfo -al -so virtual.xml
INFO: Open of `virtual.xml'
using driver `VRT' successful.
Layer name: unionLayer
Geometry: Polygon
Feature Count: 1469256
Extent: (398123.820000, 196969.360000) - (501938.600000, 260658.500000)
Layer SRS WKT:
PROJCS["British National Grid",
GEOGCS["Ordnance Survey Great Brit",
DATUM["Ordnance Survey Great Brit",
SPHEROID["Airy 1830",6377563.396,299.3249646]],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]],
PROJECTION["Transverse_Mercator"],
PARAMETER["False_Easting",400000.0],
PARAMETER["False_Northing",-100000.0],
PARAMETER["Central_Meridian",-2.0],
PARAMETER["Scale_Factor",0.9996012717],
PARAMETER["Latitude_Of_Origin",49.0],
UNIT["Meter",1.0]]
TOID: String (20.0)
FEATCODE: Integer (9.0)
VERSION: Integer (9.0)
VERDATE: Date (10.0)
THEME: String (80.0)
CALCAREA: Real (19.11)
CHANGE: String (80.0)
DESCGROUP: String (150.0)
DESCTERM: String (150.0)
MAKE: String (20.0)
PHYSLEVEL: Integer (9.0)
PHYSPRES: String (20.0)
BROKEN: Integer (4.0)
LOADDATE: Date (10.0)
AREA: Real (19.11)
LEN: Real (19.11)
SYMBOLCODE: Integer (4.0)
SHAPE_Leng: Real (19.11)
SHAPE_Area: Real (19.11)