Skip to main content
Geographic Information Systems

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Required fields*

5
  • 1
    If your data is stored in postgis, you could use a materialized view (postgresql.org/docs/12/rules-materializedviews.html) and only refresh it when needed. Commented Oct 5, 2020 at 14:42
  • I use GeoPackage and can not migrate to PostGIS Commented Oct 5, 2020 at 14:59
  • 2
    Script it and link it with a layer action. Commented Oct 5, 2020 at 15:06
  • 1
    A regular (non materialized) view would perhaps work and would be easy to test. Create the view, add it to QGIS, edit the data, pan/zoom the map and see what happens. I think you need to right-click "Update SQL Layer" on the layer to get the view to refresh within a QGIS project - see gis.stackexchange.com/questions/302302/… Commented Oct 5, 2020 at 18:55
  • 1
    Is this a hypothetical question about "cpu resources" or is this about a real world problem? If it's the former one, a good answer will include details about when virtual fields are calculated. If it's the later one, an update to the question for the problem at hand would help. Commented Oct 11, 2020 at 16:22