Cloudera 示例考试的另一个问题
Question 2
You need to write code to perform a complex calculation that takes several steps. You have decided to chain these jobs together and develop a custom composite class for the key that stores the results of intermediate calculations. Which interface must this key implement?
A. Writable
B. Transferable
C. CompositeSortable
D. WritableComparable
我相信是 D. WritableComparable。一般来说，我需要学习什么才能更多地了解 Hadoop Esco 系统的数据类型？