[postgis-users] Performance of Joins within QGIS 0.8

[Paul Ramsey]

If the problem only manfests in QGIS, perhaps this is a question for the 
QGIS list?

To try and isolate the problem, write your join as a VIEW and create the 
view in PgSQL, then try and look at the view in QGIS instead.

P

Christian Braun wrote:
> Dear members of the list,
>  
> I have serious problems with the performance of loading joins into QGIS.
> The joins are made between spatial and non-spatial tables. It seems that 
> this depends not to the size of a join. Both tables could be really 
> small in size (t1: 10col, 20rows; t2:10col, 120rows).
> Displaying or loading the join needs a lot time and the system do not 
> react any more. Once the join is loaded as a layer the working speed is 
> gone to normal and good. Queries on tables and listing attributes is 
> working fine also. Also the displaying of the data in pgadmin or on the 
> commandline interface is good and fast, so I guess it does not depend on 
> indicies and vacuuming the database.
> I tested it with version 0.74 and 0.8 of QGIS on Windows and on Linux 
> (Ubuntu 6.06 and 6.10) machines. Also locally on the database server as 
> well as over a network connection to the server.
>  
> Anyone of you have an idea whats going on here?
>  
> Thanks in advance,
>  
> Christian
> 
> _________________________________________
> 
> Mit freundlichen Grüßen
> 
> Dipl. Geogr. Christian Braun
> Mail: christian.braun at tudor.lu <mailto:christian.braun at tudor.lu>
> 
> Resource Centre for Environmental Technologies,
> Public Research Centre Henri Tudor,
> Technoport Schlassgoart,
> 66 rue de Luxembourg,
> P.O. BOX 144,
> L-4002 Esch-sur-Alzette, Luxembourg
> 
>  
> 
> 
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   Paul Ramsey
   Refractions Research
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   pramsey at refractions.net
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