I have managed to get qgis to show my Mastermap data which is stored in a postGis database. It's national coverage so seems to take ages to load but that's another question.

I basically want to export the map that I can see (or at least one layer of it) as a DXF.

When I try to do this (layer save as) it starts to generate a temp version of the dxf file but then just hangs and I have to use task manager to close it and start all over again. It's as if it's trying to read the whole database.

The postGis database was created using Edonica. Some of the field names are different to those you get if you load a gml file directly in to qgis so this may be the problem. Or do I have to make a selection of the area I want?

Thanks for any help


  • how are you extracting out the postgis mastermap data to dxf? - you might need to restrict the extent to stop the 'hanging' what spec does the postgis db (server) have? – Mapperz Sep 11 '12 at 13:39
  • I'm just doing the Save As option on the Layers menu. The postgis is running on a virtual so is not that powerful. How do you limit the extent? I tried selecting an area but that didn't seem to do anything? – Graham Sep 11 '12 at 14:25
  • Thanks for the link but that looks highly complex to me. I need this to be doable by non-technical staff. Surely it can't be that complicated? – Graham Sep 12 '12 at 8:18
  • If I added the bbox column then how would I modify qgis to make use of that by default or would the query optimiser make use of it without the user having to know about it? – Graham Sep 12 '12 at 8:27

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