[Qgis-user] GeoPackage deadlocks

[Even Rouault]

On vendredi 25 octobre 2019 17:10:40 CEST Matthias Kuhn wrote:
> Hi all,
> 
> We had the same experience in a project of ours. Multiple users with
> read-only access to a gpkg on a (Windows) network share. The results
> were freezes on unloading the layer (e.g. closing QGIS or opening
> another project) on system A until system B would have closed the QGIS
> layer there. The behavior seemed surprising to me and on first sight I'd
> have put it more into the category "bug" rather than "feature".
> 
> Good news, this behavior could be changed by switching the sqlite
> journal mode to delete (environment variable OGR_SQLITE_JOURNAL=DELETE).

Caution: WAL was enabled because DELETE (which is the default journal mode of 
SQLite) was causing locking issues, even in local file, single user, single 
QGIS application context. There might have been later changes in the OGR 
provider that makes it no longer needed, but this should be carefully checked. 
In particular if the test added in https://github.com/qgis/QGIS/commit/
b6b8759efbeb833d0d3dbf6df008087701361ad3#diff-17fd782357fcfed115b06d24b4416bbdR92 
still pass in DELETE

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com