[Qgis-user] QGis checks uniqueness of primary key on startup

[Bernhard Ströbl]

Hi,

if a relation is a table with a unique primary key QGIS has no need to 
scan for uniqueness (AFAIK)
so you could create a table or materialized view [1] (does anybody have 
any experience with MV and QGIS?) to store your data and make sure that 
it is always up to date
Another idea I would try is to create several views with less data each 
based on the spatial index or the primary key (notice: I have not tried 
if it is faster to load 20 layers à 1 million features, but it may be 
faster once they are in the project)
BTW is the uniqueness scan done every time the project with the layer is 
loaded or only when loading it using the load dialog?

if you find a solution please report back to the list

Bernhard

[1] 
http://www.postgresql.org/docs/9.3/static/sql-creatematerializedview.html

Am 20.05.2014 15:58, schrieb Jürgen E. Fischer:
> Hi Flo,
>
> On Tue, 20. May 2014 at 14:17:23 +0200, Florian Lohoff wrote:
>> It does so twice by the way - once to check for uniqueness, once
>> to do an st_extent on the geometry ...
>
> If you don't "use estimated table data".
>
>
> Jürgen
>

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