[QGIS-trac] Re: [Quantum GIS] #1855: Postgis View Layers with OID as primary key are loading very slow

[Quantum GIS]

#1855: Postgis View Layers with OID as primary key are loading very slow
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        Reporter:  hdus              |         Owner:  jef          
            Type:  bug               |        Status:  new          
        Priority:  minor: annoyance  |     Milestone:  Version 1.2.0
       Component:  Data Provider     |       Version:  HEAD         
      Resolution:                    |      Keywords:               
Platform_version:                    |      Platform:  All          
        Must_fix:  Yes               |   Status_info:  0            
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Comment (by hdus):

 Replying to [comment:3 jef]:
 > Replying to [ticket:1855 hdus]:
 > > I want to load a postgis view layer defined in a way that the OID
 represents the primary key of the view query result. No real primary key
 is defined in the source tables. When I query this view from psql it gives
 me the query result very fast. When I load this layer into QGIS it needs a
 very long time, more than 1 minute, to load this layer.
 >
 > Does "loading" mean only "inserting" or "displaying"?   Inserting the
 view to the project can be slow, while QGIS tries to figure out what the
 primary key column is.   Once that's done displaying should be quick.
 Saving the project and reloading it should be also quick as QGIS saves the
 key column it found.
 >
 > If you add the layer using python you can also specify the key column
 using key=column and QGIS will just verify that it's unique.
 >
 > See also #1535

 Loading means inserting. I took a look at the comments of #1535 and there
 gjm talked about an option to select the primary key column by the user
 when he is loading the postgis layer. Maybe it is possible to make some
 changes of the Postgis loader UI in this direction?

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Ticket URL: <https://trac.osgeo.org/qgis/ticket/1855#comment:4>
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