Are AMP Worker Tasks used by FastExport in Response Mode? - comment by carrie

Idle sessions are sessions that are between database requests.  They do not have any active work that could be holding AMP worker tasks on the AMPs. 
 
And you are correct that there is no machanism to tie a specific use to current AWT usage.  The only way you could maybe make that work is if you set up a special workload in TASM just for a single user, then monitored the AWT usage for that workload across all nodes, using the ResUsageSPS table.  That's a pretty limited approach and I don't think it's worth the effort, since you can look at a query plan and make an educated guess at how many AWTs were in use during the different steps of the plan.
 
Thanks, -Carrie