<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">yes, that would generate/utilize a local Spatialite DB or Python RTree “working area” , could be quite powerful, especially if somehow exposed as Python objects, and/or integrated with the Processing framework …<div class=""><br class=""></div><div class="">Chris<br class=""><pre class="">
><i class=""> On Sat, Feb 18, 2017 at 8:41 PM, Anita Graser <<a href="https://lists.osgeo.org/mailman/listinfo/qgis-developer" class="">anitagraser at gmx.at</a>> wrote:
</i>><i class="">
</i>>><i class=""> Hi,
</i>>><i class="">
</i>>><i class=""> I'm looking for a better way to handle stationary objects in Time
</i>>><i class=""> Manager.
</i>>><i class=""> For example, think of a real estate map, where plots of land change value
</i>>><i class=""> over time. The geometries themselves rarely ever change.
</i>>><i class="">
</i>>><i class=""> Currently. It is necessary to create a join of plot geometries and values
</i>>><i class=""> over time, duplicating geometries and creating potentially huge layers.
</i>>><i class="">
</i>>><i class=""> So far, my thoughts are going in the direction of creating query layers
</i>>><i class=""> for such cases. The query layer definition could be controlled by Time
</i>>><i class=""> Manager, to always update according to the requested time frame.
</i>>><i class="">
</i>>><i class=""> Does that sound reasonable? Do you have other ideas or are there any
</i>>><i class=""> plans about adding temporal support to QGIS3 that I should be aware of?
</i>>><i class="">
</i>><i class="">
</i>><i class="">
</i>><i class=""> Experiments so far (with 2.18) have turned up that virtual layers don't
</i>><i class=""> seem to support getProvider().minimumValue()
</i>><i class=""> which makes them unusable in Time Manger.
</i>><i class="">
</i>
That is minimumValue() and uniqueValues() seem to always just return None.
Best wishes,
Anita</pre><div class=""><br class=""></div></div></body></html>