[QGIS-Developer] DB-manager and large query results (for time manager)

[Raymond Nijssen]

There's a question on a Dutch geo forum about a join query in DB-Manager 
that does not return data, but an error without message instead. PG 
Admin runs the query with he expected results, so it seems ok.

People have been trying to reproduce this with different results.

The query is joining a layer with 355 detailed polygons (municipalities) 
to a table with timestamps and values for every day (covid numbers). The 
result multiplies the polygon data for every day, copying the polygons 
over 50k times.

Questions:

1
Does the DB-Manager or QGIS or something else kill the query because the 
results (can) get too large?

2.
Is there a more efficient way to use time manager in combination with 
large geometries, in a case where only the time values change and not 
the geometries?

Here's the link to the Dutch thread:
https://geoforum.nl/t/lege-foutmelding-db-manager-na-join/4667


Thanks for any help!

Raymond

PS In my 3.15 opening the DB-manager crashes my QGIS instandly, so I 
could only test the query in 3.12 without the time manager.