Even Rouault <even.rouault at spatialys.sys> writes: > The default enabling of WAL even in initial read-only access mode is > to avoid that potential issue. > > There are currently way of disabling WAL (for advanced users) : > > - setting the OGR_SQLITE_JOURNALenvironment variable to JOURNAL > - or setting the QGIS setting "qgis/walForSqlite" to false > > See > https://github.com/qgis/QGIS/blob/master/src/core/providers/ogr/qgsogrprovid erutils.cpp#L1005
Greg Troxel <gdt at lexort.com> writes: > Thanks for the pointers; I think I am beginning to follow. > The use of WAL is a persistent property of a database. Clients use it > or not when connecting, normally. > As it is, qgis (by default) forces WAL mode, even if the database was > not already in WAL, and even if there are other connections open. Or > it forces DELETE mode, similarly without checking. So the concern > about upgrading/downgrading comes from any setting of mode by any > connection and any other existing connection. > After digesting it all, I am left thinking that whether to use a geopackage in WAL mode or DELETE mode is a user decision, ... > Therefore, I think the right approach is: > 1) let the user do "pragma JOURNAL_MODE=WAL;" if they want > 2) when opening the database, don't do anything about JOURNAL_MODE; just use it the way it is set. You've left me in the dust, which is fine. But it sounds that A. Ideally WAL/DELETE would be a connection (in the sense of the Browser connections list) level decision changeable by the user, not a layer-level decision and not (as now) an application setting used for all gpkg connections. In the distant future, I could see the Browser providing a UI wrapper to send the right pragma JOURNAL_MODE if user requests. B. Currently, one option would be for me/others to set qgis/walForSqlite to false, which would solve the problem for readonly gpkgs and only slightly downgrade performance for (modest-sized) writeable gpkg primarily edited via the canvas. C. Alternately, continuing to let QGIS use WAL, but setting the specific .gpkg file to be read-only in the file system is a harmless if crude solution (as long as I have no intention of actually editing the layers in that gpkg). Do I have that right? Thanks! Martin _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user