Segment Repartition Showplan Operator
In a parallel query plan, sometimes there are conceptual regions of iterators. All of the iterators within such a region can be executed by parallel threads. The regions themselves must be executed serially.
Some of the Parallelism iterators within an individual region are called Branch Repartition. The Parallelism iterator at the boundary of two such regions is called Segment Repartition.
Branch Repartition and Segment Repartition are logical operators.