Q44 — AWS DEA-C01 Ch.1

Question 44 of 100 | ← Chapter 1

A company uses an Amazon Redshift provisioned cluster as its database. The Redshift cluster has five reserved ra3.4xlarge nodes and uses key distribution. A data engineer notices that one of the nodes frequently has a CPU load over 90%. SQL Queries that run on the node are queued. The other four nodes usually have a CPU load under 15% during daily operations. The data engineer wants to maintain the current number of compute nodes. The data engineer also wants to balance the load more evenly across all five compute nodes. Which solution will meet these requirements?

• A. Change the sort key to be the data column that is most often used in a WHERE clause of the SQL SELECT statement.
• B. Change the distribution key to the table column that has the largest dimension ✓
• C. Upgrade the reserved node from ra3.4xlarge to ra3.16xlarge.
• D. Change the primary key to be the data column that is most often used in a WHERE clause of the SQL SELECT statement.

Correct Answer: B. Change the distribution key to the table column that has the largest dimension

Explanation

在AmazonRedshift中，数据分布不均可能导致某些节点负载过高，而其他节点负载过低。要平衡节点负载，需要调整数据分布。选项A和D提到的改变排序键和主键，虽然会影响查询性能，但不会直接解决节点间负载不均的问题。选项C提到的升级节点类型，虽然可以提高单个节点的处理能力，但并不能保证负载会均匀分布到所有节点。选项B提到的改变分布键到具有最大维度的表列，可以直接影响数据的分布，从而更有可能实现节点间的负载平衡。因此，B选项是满足要求的解决方案。