Updates for tempdb groups for version 15.5
Adaptive Server allows you to create and manage user-created tempdb groups in addition to managing the default tempdb group. User-created tempdb groups can include other user-created temporary databases, and support application and login binding.
You cannot remove the system tempdb from the default temporary database group. You cannot add system tempdb to any other user-created tempdb group.
You can designate and administer user-created tempdb groups to contain only disk-resident or in-memory temporary databases. The server does not explicitly impose any such restriction, but by controlling the membership you can assign disk-only or in-memory-only tempdb groups to specific logins or applications.