Bug report #18341

VRT loads extremely slowly

Added by matthieu carlini over 2 years ago. Updated almost 2 years ago.

Status:Closed
Priority:High
Assignee:-
Category:Rasters
Affected QGIS version:3.0.0 Regression?:Yes
Operating System:windows 7 pro Easy fix?:No
Pull Request or Patch supplied:No Resolution:no timely feedback
Crashes QGIS or corrupts data:No Copied to github as #:26231

Description

Opening a VRT layer takes a lot of time on version 3.0.
tested on a 341ko file that references 273 ecw files :
- time on QGis 2.18.16 : 00:36:21
- time on QGis 3.0.0 : 12:26:24

History

#1 Updated by Giovanni Manghi over 2 years ago

  • Priority changed from Normal to High
  • Status changed from Open to Feedback

#2 Updated by Giovanni Manghi over 2 years ago

What about 3.2? any chance the dataset can be shared?

#3 Updated by Alexander Bruy almost 2 years ago

  • Resolution set to no timely feedback
  • Status changed from Feedback to Closed

Closed for the lack of feedback. Please reopen if necessary.

#4 Updated by Alain FERRATON almost 2 years ago

according to my tests.
during the first opening QGIS calculates statistics for the VRT which is very long. He adds them to the VRT when closing.

It is possible to pre-calculate the statistics with
gdalinfo -approx_stats My_vrt.vrt

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