[Qgis-user] Thrashing after toggling editing off

[Jeff Hubbs]

I'm observing this behavior under 3.4 on Linux and OS X Catalina and 
3.10 on OS X Catalina. I use Field Calculator on a vector layer to 
create a new field with $area values. I toggle editing off hoping to 
save the layer with its new field and the system thrashes on one thread, 
about 1/3 system and 2/3 user. Plenty of RAM, no swapping. The modify 
time of the .dbf file that would be being written keeps getting advanced 
to the current time but it doesn't get any bigger. The app is 
unresponsive and the cursor spins while hovering over it. What's going 
on in there, and why?

Thanks,

Jeff