Detached transactions are meant to persist in Adaptive Server, since the client application may want to reattach the original thread, or attach a new thread to the transaction. The System Administrator can no longer roll back a transaction by killing its associated spid, as a thread is not attached to the transaction.
Transactions in a detached state may also prevent the log from being truncated with the dump transaction command. In extreme circumstances, detached transactions can be rolled back by using the new dbcc complete_xact command to heuristically complete a transaction. See “Heuristically completing transactions”.