[Qgis-developer] Using PostGIS on a slow connection

Martin Dobias wonder.sk at gmail.com
Wed Feb 26 18:17:11 PST 2014

Hi Andreas

On Wed, Feb 26, 2014 at 9:48 PM, Andreas Neumann <a.neumann at carto.net> wrote:
>> Some of the slowness is understandable, some not really, e.g. why
>> deactivating a layer in the legend should require time?
> that's a case where the render-cache should work. When deactivating a
> layer, QGIS will just redraw all remaining visible layers. In case the
> render-cache was active it would just draw the layers from the cache.
> Unfortunately the render cache introduced issues and did not work well
> with certain data providers (e.g. WMS). That's why I do not use it
> currently.
> Maybe Martin could comment if the idea of the render-cache is still
> feasible or useful at all with the new multi-threaded renderer.

It should be safe to use render cache now in master branch, even with WMS.

Paolo: make sure you have render caching turned on. Deactivating (and
activating again) a layer should be immediate. Of course, if you pan
the map or zoom in/out, everything will be re-rendered.


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