Databricks Data Engineer Associate Question 188
Single answerYou are working with a nested JSON dataset in Databricks that contains an array of objects under a column named 'events'. Each object in the array represents an event with fields such as 'event_name' and 'timestamp'. You need to create a row for each event while preserving the other fields in the dataset. Which function should you use?
- A
explode()
- B
flatten()
- C
collect_list()
- D
array_contains()
Show answer and explanation
Correct answer: A
Explanation
The explode() function is used to create a new row for every element in an array while keeping other columns intact. This is ideal for scenarios where you need to expand a nested array into individual rows for further processing, such as analyzing each event in the 'events' array. flatten() is used to combine arrays of arrays into a single array, which is not applicable in this case.
- A. Correct.
explode() is correct because it transforms each element in an array into its own row while preserving the other columns in the dataset.
- B. Incorrect.
flatten() is incorrect because it works on arrays of arrays and merges them into a single array, but it does not generate rows for each element in the array.
- C. Incorrect.
collect_list() is incorrect because it aggregates rows into a list but does not break out elements into individual rows.
- D. Incorrect.
array_contains() is incorrect because it checks if a specific value exists in an array and does not change the structure of the dataset.