User Kernel Thread (UKT) 

A database instance contains a series of threads. A user kernel thread (UKT) forms a subset of all tasks (for internal tasking).

The following types of tasks exist:

·        Pager

·        Log Writer

·        Server Task

·        Timer Task

·        Trace Writer Task

·        User Task

·        Utility Task

Each user kernel thread can contain one or more tasks. The task states give you information on the corresponding thread.