Here’s the Connect Item involved – written by Michael Swart.
Trace flag 2390 can cause large compile time when dealing with filtered indexes. (Active)
https://connect.microsoft.com/SQLServer/feedback/details/2528743/Huh. “What does that have to do with clustered columnstore indexes?” you might ask. No, really, it’d be a personal favor if you *did* ask…
Ask and then read on. This is the kind of post I’d send to someone wanting to learn how to troubleshoot issues.