Bug report #9519
Rollback operations slow if lots of features changed
|Affected QGIS version:||master||Regression?:||No|
|Operating System:||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:||duplicate|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||18109|
- Open a layer with a big amount of features (...and with a slow backend)
- Start editing
- Open the field calculator
- Create a new column (e.g. "rand( 1, 10 )" )
- Stop editing without saving changes
It takes a long time to undo this command and QGIS freezes during this time. As far as I can tell, there are feature requests made for every single feature which was updated before (so all in the case mentioned above).
I could imagine a possible approach would be to batch undo the affected rows and perform a single request with setFilterFids() to still only request the required rows, but with less roundtrips.