Hi

On Mon, Mar 14, 2011 at 3:21 PM, Windmuller, H (Hans)
<[email protected]> wrote:
> LS,
>
> We are using Quantum GIS for our wardens. I have a question of which I don't 
> know where I can put it so I'm hoping one of you can get me into the right 
> direction.
>
> On our clients we have Windows XP sp2 as Operating System and on our 
> fileservers we have Microsoft Server 2003 as Operating System.
> We store our data files (shape files and raster files (ecw)) on the central 
> file server.
> For a shape file with a .shp file (size 3 MB) and a .dbf file (size 155 MB) 
> it takes 7 minutes and 30 seconds to get the shape displayed on screen. 
> Between the two locations there is a WAN of 10 Mbps.
>
> Other applications (MapWindow, ArcGIS, DIVA-GIS) only take 40 seconds to do 
> the same.
> My presumption is that Quantum GIS first downloads the entire shape file onto 
> the client before rendering. The other applications seem only to download the 
> .shp file and to approach the .dbf file on the file server.
>
> I have observed that it is the .dbf file that is taking the time because when 
> I deleted a number of fields in the specific .dbf file time dropped to about 
> 3 minutes (and the size of the .dbf file dropped to 85 MB).
> The other applications still gave the same result of 40 seconds.
>
> Can someone of you please tell me how Quantum GIS handles shape files on a 
> remote file server and if / when Quantum GIS will be able to get the same 
> results in performance as the other applications mentioned above?
>
> I'm looking forward to receiving your answer.
>
>

Since we are using gdal/ogr for reading shapefiles, this is probably a
question better asked on the gdal mailing list. Let us know if you get
some interesting response from them!

By the way for such a client / server environment, it is *much* better
performance wise and logistically to put your data into PostGIS.

Regards

Tim


> Kind regards
> Met vriendelijke groet,
>
> Hans Windmüller
> medewerker GIS
> Rijksweg 501
> 1991 AS  VELSERBROEK
> 0251-661035
> 06-53792012
> [email protected]
> www.pwn.nl
>




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