I have a large table in Postgis2. It has >500 million polygon, line and point features all happily living in there and the table performs brilliantly in other GIS.

I am now trying to just add that table to a project in QGIS but here is the thing, why does it take so long?

When i try to 'Add PostGIS overlay' it says detecting for about 4 hours to tell there are 3 geometry types.  OK, i can take that if i only have to do it once...

Once it finishes that i select all three parts click ok..  so far im 2 days into trying to get it to load into the canvas.

What is going on?  I am zoomed in so only a few polygons should be rendered on screen.

Is this an error or a 'feature' of QGIS?  Is there something i need to specifically do to enhance the performance for QGIS? 

Many thanks for your help people.