delete sum and avg field but not deleted.

[songying2013]

When I am in Sources > Tables > Edit Record > List Columns , I delete some field, but after I save the edit, it still there.

[mistercrunch]

That's the intended behavior, for now you have to manually delete the metrics as well. If we'd just delete metrics there's high potential for breaking existing charts unknowingly...

#4663 changes the way this is done, and make it much easier to define metrics.