Preparing Results Takes A Long Time

[akikax]

Eveyone, my issue is effectively already captured and discussed here

UI (Preview) query not accelerated

I have a dataset (D2) based on another dataset (D1) that has raw reflection turned on. When selecting D2 from the UI it automatically executes in preview mode (haven’t figure out how to turn that off). That query never gets accelerated because it says the D1 reflection doesn’t cover the query. However, when I select RUN to execute the query it does use the D1 reflection. The net result is the preview takes much longer to execute then just running the query. Are there any use cases where this is…