[Qgis-user] How to Prevent GeoPackage file from updating modified date when viewed in a Qgis project when it is not being edited

[Even Rouault]

On mardi 10 avril 2018 08:11:30 CEST Richard Duivenvoorde wrote:
> On 09-04-18 22:22, Even Rouault wrote:
> > Or perhaps have some option in a dialog box somewhere! "I promise that I
> > will not edit this file in any concurrent session, or in this session, so
> > you can safely open it in DELETE mode" ? Or spend more time digging again
> > into the details of sqlite locking to see if we could make a clever use
> > of it, and/or possibly improving it in sqlite itself (rather involved!)
> 
> I would be ok with an option in the dialog, though it is hard to promise
> that somebody *else* will not open it too in a non readonly mode, in a
> networked work environment ...

You'll have issues with sqlite in a networking environment, as WAL cannot work 
in that context (QGIS does some effort to detect if the file location is a 
network driver or not, before deciding to turn WAL on). So you'll get the 
default journaling behaviour, which is lock prone.

> 
> Is it a possibility (at least on linux) to look at the file permissions?
> That would open the possibility to put a read-only (permissioned) file,
> and in that way you would promise to not edit/delete?

Just tested: QGIS can open file a read-only .gpkg on Linux (it will fallback 
to the default journaling mode), and presumably on Windows as well.

Or were you talking about some side car files that would be used to 
application level locking ?

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