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

[Florian Lohoff]

On Tue, May 20, 2014 at 11:55:51AM +0000, Andreas Neumann wrote:
> I agree - you have to put scale constraints in the symbology of an
> address table with 20 million records. Displaying all at once wouldn't
> make any sense. Most likely, every pixel of your screen would be covered
> if you want to display them all.

I have - I dont expect 20 Million object to be rendered :) 

> On our cadastral map with only a couple thousand of address points we
> display house numbers from scale 2000 - otherwise you would have too
> many labels and the map gets illegible.

Thats not my problem - even on start at a scale of 1:8000 QGis does
a full table scan on that table to check for uniqueness of the key.

It does so twice by the way - once to check for uniqueness, once
to do an st_extent on the geometry ...

Flo
-- 
Florian Lohoff                                                 f at zz.de
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