Just browsing for some more information on this operation, and it just happened that my favorite VizPlan expert has chimed in here 
I have a scenario where I am using a nested SQLScript based calc view. One view (child view) retrieves a relatively small data set, then the main CV takes that and joins with a bunch of other data from another schema.
When I started out, just the nested portion of (child calc view), takes roughly 800ms to return it's resultset, for which I was pleased. Now, when I added some other joins onto that dataset in the main CV, I am seeing my runtime spike to approximately 16 seconds, with 15 seconds being spent on a "Create Temp Index" process that only results in 12 rows (from what I can see).
Now the question becomes - since I have identified where 95+% of my runtime is being generated, how can I really pinpoint what operation is causing this? I was thinking the ID column (shown in the details) may offer some clues if one knew how to locate the details in a system table somewhere?
Otherwise, all I can see in the VizPlan is that YES there is a long running component, but I have no idea what it might be, therefore can't do anything about it 
Regards,
Justin