QGIS slows down dramatically if 'ask for datum transformation' dialog option is on

[qgib]

Author Name: Regis Haubourg (@haubourg)
Original Redmine Issue: 9827
Affected QGIS version: 2.2.0
Redmine category:projection_support

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Qgis slows down dramatically when opening projects with layers in differents projections, if that option is enabled.
Not showing the dialog does a good workaround the issue.
This is a real blocker, discovered on the first 2.2 release training day here. Every client was stucked sometimes for 20 minutes.. Really hard to diagnose indeed.
Would be really great to backport.
Cheers
Régis

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• bug_qgis_22.png (Regis Haubourg)

[qgib]

Author Name: Michael Douchin (@mdouchin)

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Hi,

You mean when on-the-fly projection is enabled, and the project contains several layers with different CRS ?
In the workaround mentionned, which dialog are you talking of ?

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Salut Michael.
The mentionned dialog is in attached file. Problem remains if qgs file properties where saved with OTF Off.

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• 7013 was configured as bug_qgis_22.png

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• bug_qgis_22.png (Regis Haubourg)

[qgib]

Author Name: Marco Hugentobler (@mhugent)

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From the description, it is not clear to me what you mean by 'slowness'. Is it a) that the users had to make a choice for the datum transformation when opening projects saved with older versions (and click 'remember') or b) was the application also slower if all the datum transform information has been present?

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• status_id was changed from Open to Feedback

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Well, after the first dialog warning for older qgs version, then, layers are loaded. First layers are loaded fast, until a layer requiring reprojection is hit. No datum dialog raise, but QGIS waits for sometimes 10 minutes on each layer after that..

I will check if list of datum reprojections set in general option has an effect..

[qgib]

Author Name: Martin Dobias (@wonder-sk)

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Please test again if the problem persists in current master (there have been some changes in the implementation)

[qgib]

Author Name: Pedro Venâncio (Pedro Venâncio)

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I can confirm this in QGIS 2.2, not only when opening a saved project, but also when adding two layers (it's more noticeable with heavy layers) with different datum. The datum transformation dialog box takes a long time to appear.

With QGIS master, everything seems to be resolved.

[qgib]

Author Name: Giovanni Manghi (@gioman)

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Please reopen if necessary.

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• resolution was changed from to fixed/implemented
• status_id was changed from Feedback to Closed