Bug report #5049
Data-defined labeling takes 1560% longer to render
Status: | Closed | ||
---|---|---|---|
Priority: | Normal | ||
Assignee: | - | ||
Category: | Labelling | ||
Affected QGIS version: | master | Regression?: | No |
Operating System: | Easy fix?: | No | |
Pull Request or Patch supplied: | No | Resolution: | fixed |
Crashes QGIS or corrupts data: | No | Copied to github as #: | 14819 |
Description
- No labels: ~2.5 sec
- Labels with field NAME and no data-defined setting: ~8.0 sec
- Labels with field NAME and data-defined size set to POP_2000: ~41.6 sec
That's a 420% time increase over labeling with no data-defined setting and 1560% longer than no labeling at all.
Time was calculated with stopwatch, between pressing OK on the labeling dialog and when the map finally appears.
Related issues
History
#1 Updated by Aren Cambre almost 13 years ago
I ran this test on a laptop with 8 GB RAM (several GB free) and Intel Core i7 Q720 (1.6 GHz).
#2 Updated by Aren Cambre almost 13 years ago
Related: #5048
#3 Updated by Marco Hugentobler almost 13 years ago
This is because in POP_2000, there are huge values. If you set the font size e.g. to 1000 (points), you get long rendering times also if the size is not data-defined.
So the longer rendering is only because the labels are larger (over 1000000 points for Houston).
#4 Updated by Aren Cambre almost 13 years ago
Ah, so looks like resolution of #5048 might be necessary to fix this performance issue?
#5 Updated by Jürgen Fischer almost 13 years ago
Aren Cambre wrote:
Ah, so looks like resolution of #5048 might be necessary to fix this performance issue?
or by using an attribute that is usable as size - eg. by using the field calculator to produce a appropriately scaled value in an additional attribute.
#6 Updated by Paolo Cavallini about 12 years ago
- Target version set to Version 2.0.0
#7 Updated by Nyall Dawson over 11 years ago
- Status changed from Open to Feedback
This might be closable now -- this can be achieved by using an expression for the definition and using the new "scale_linear" function.
#8 Updated by Larry Shaffer over 11 years ago
- Status changed from Feedback to Resolved
- Resolution set to fixed
Should be fixed with commit 45f374f4
Reopen if necessary
#9 Updated by Jürgen Fischer almost 11 years ago
- Status changed from Resolved to Closed