Q72 — AWS DEA-C01 Ch.1

Question 72 of 100 | ← Chapter 1

A data engineer wants to improve the performance of SQL queries in Amazon Athena that run against a sales data table. The data engineer wants to understand the execution plan of a specific SQL statement. The data engineer also wants to see the computational cost of each operation in a SQL query. Which statement does the data engineer need to run to meet these requirements?

• A. EXPLAIN SELECT ∗ FROM sales;
• B. EXPLAIN ANALYZE FROM sales;
• C. EXPLAIN ANALYZE SELECT ∗ FROM sales; ✓
• D. EXPLAIN FROM sales;

Correct Answer: C. EXPLAIN ANALYZE SELECT ∗ FROM sales;

Explanation

在AmazonAthena中，如果数据工程师想要了解特定SQL语句的执行计划，并查看每个操作的计算成本，需要使用“EXPLAINANALYZE”语句。对于给定的销售数据表“sales”，完整的语句应该是“EXPLAINANALYZESELECT*FROMsales;”。选项A仅能提供执行计划，无法给出计算成本；选项B缺少具体的查询语句；选项D同样不完整，无法满足要求。所以，选项C是正确答案。