[QGIS-Developer] SQLite/GPKG database locked during canvas refresh... is it a feature?

[Luigi Pirelli]

can make sense a solution like this one?
https://github.com/qgis/QGIS/pull/5305
Luigi Pirelli

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On 4 October 2017 at 17:54, Matthias Kuhn <matthias at opengis.ch> wrote:
> Hi Luigi,
>
> It sounds like a very crappy UX the way this is described.
>
> The second way you describe sounds like a reasonable one to go.
>
> However, most dataprovider handle this cleanly on a different level (if
> you have an iterator open on a pg layer, it will keep delivering
> features from the snapshot when the query was sent, and allow to modify
> in parallel). So rendering shouldn't be stopped in any case, but only
> when it's really required.
>
> Actually there may also be other code besides rendering reading from
> such a format while trying to save. So in the long run we'll need
> something else.
> Probably schedule a task that waits for any readers to be finished and
> then saves once the lock is gone (and tell the user that the save has
> been deferred).
>
> Matthias
>
> On 10/04/2017 04:46 PM, Luigi Pirelli wrote:
>> Hi
>>
>> the bug described in https://issues.qgis.org/issues/15498 IMHO is a
>> feature instead of a regression... any opinion?
>>
>> my rational is:
>>
>> """Ok, it can be a regression, but IMHO the behaviour is correct in
>> this way respect allowing to write during rendering.
>> If layer is modified during rendering, theoretically rendering have to
>> be invalidated. Stopping rendering is always possible with rendering
>> checkbox in the bottom bar => the correct procedure would be:
>> 1) stop rendering
>> 2) save features
>> 3) refresh
>>
>> or
>>
>> 1) during save => stop rendering
>> 2) save edit
>> 3) refresh
>>
>> the above would be a new feature that is not strictly necessary
>> because of manual workaround.
>>
>> can it be considered a low priority issue, and more, can it be
>> considered a fix instead of a regression"""
>>
>> Luigi Pirelli
>>
>> **************************************************************************************************
>> * Boundless QGIS Support/Development: lpirelli AT boundlessgeo DOT com
>> * LinkedIn: https://www.linkedin.com/in/luigipirelli
>> * Stackexchange: http://gis.stackexchange.com/users/19667/luigi-pirelli
>> * GitHub: https://github.com/luipir
>> * Mastering QGIS 2nd Edition:
>> * https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition
>> **************************************************************************************************
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