Answer:
C
The Scheduler enables you to specify the database service under which a job should be run (service affinity). This ensures better availability than instance affinity because it guarantees that other nodes can be dynamically assigned to the service if an instance goes down. Instance affinity does not have this capability, so, when an instance goes down, none of the jobs with an affinity to that instance can run until the instance comes back up. Figure 28-8 illustrates a typical example of how services and instances could be used.
版权声明：本文为博主原创文章，未经博主允许不得转载。
原文：http://blog.csdn.net/adeline_pan/article/details/46849521
