[Qgis-user] [QGIS-Developer] Model for Temporal Measurement (vector) Datasets ?

Richard Duivenvoorde rdmailings at duif.net
Sun Sep 4 06:17:43 PDT 2022


On 9/4/22 14:35, Tim Sutton wrote:
> Hi Richard
> 
> Don’t people normally use things like https://www.timescale.com/ <https://www.timescale.com/?utm_source=timescaledb-paid&utm_medium=google-search&utm_campaign=brand-2022&utm_content=homepage&utm_term=timescale-postgres&gclid=EAIaIQobChMIspXn6JL7-QIVOpBoCR3QLQf8EAAYASAAEgL09PD_BwE>
> 
> For this? In any case some of our clients that are doing things like vehicle tracking are…

Yes to *store* it, but my point is: given 2 points with 100 timesteps, QGIS will create 200 features for it to be able to display it...
So to 'view' that data in (Q)GIS, you have to flatten it to a 'table' with 200 features...

While the actual interesting part is the value and the time, NOT those 2 xy fields... (the case of moving vehicles is slightly different, there the xy values also change)...
Maybe I'm in the wrong crowd here to tell the geoms are not so much of interest in my case ;-)

I'm looking for a way/model (non tabular) that QGIS creates 2 geometries/features, and then will style/paint it based on the timestamps and values

The use case here: having 5000 sensors in Europe, having 500.000.000 measurements in total, I don not want to create 500.000.000 features.

I'd preferred to create those 5000 features, and then get the geom-id/value/timestamp for a given filter range and repaint my canvas.

Something like 'dynamic' joins: the geometries will stay the same, but the 'joined' columns/table will change based on the 'temporal filter' requested.

Sorry if I can not make myself more clear (or making it more complex that it maybe is...) :-)

Regards,

Richard Duivenvoorde


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