Use the Query Profile to Analyze the Query and Identify Bottlenecks, Such as Bad Data Skipping, Inefficient Types of Joins, and Data Shuffling. DATA-ENGINEER-PROFESSIONAL Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   In the Databricks query profile, which component provides a high-level breakdown of the query execution into phases such as scan, shuffle, and aggregation?

   • AThe cluster event log
   • BThe metrics tab
   • CThe query plan diagram
   • DThe SQL text pane
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A query profile shows that one task in a stage takes 15 minutes while all other tasks take less than 1 minute. The stage has 200 tasks. The query is a join on a column with a skewed distribution. Which action would most likely resolve the skew?

   • AIncrease the number of shuffle partitions
   • BUse a broadcast join on the large table
   • CAdd a salt to the join key to distribute the skewed keys across more tasks
   • DReduce the number of executors to increase resource per task
   Reveal Solution Discussion Select an answer first
4. 8foundation · easy

   Which query profile metric is most useful for identifying excessive I/O caused by reading too much data from storage?

   • ANumber of output rows
   • BBytes read
   • CShuffle write time
   • DNumber of shuffle partitions
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   Which query profile observation is a sign of excessive data shuffling?

   • AA low number of tasks
   • BA large shuffle write size accompanied by a high shuffle read size
   • CA high number of output rows
   • DA high bytes read from storage
   Reveal Solution Discussion Select an answer first
6. 10foundation · easy

   In the query profile, which metric indicates the effectiveness of data skipping?

   • ANumber of tasks
   • BShuffle read size
   • CNumber of files scanned
   • DDuration of the scan operator
   Reveal Solution Discussion Select an answer first