Databricks · Databricks Data Engineer Associate
Columns, rows, and aggregates
Databricks Data Engineer Associate · Lesson 10 of 22 · 1:05:17
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In this lesson
Prepare for the Databricks Certified Data Engineer Associate exam. In this lesson: adding, renaming, and dropping columns, filtering and exploding rows, removing repeated rows, and aggregates with groupBy and approximate distinct counts. Includes three original practice questions.
Preview the topics
- Each loyalty event has a basket column that holds an array of items, and the analysts need one row per item, with the member ID on each row. Which function fits?
- The app sometimes sends the same event twice, with the same event ID but a different arrival time, so the rows are not identical. The silver table needs one row per event ID. What should the data engineer use?
- A daily dashboard shows the number of distinct members who visited each store, from billions of loyalty events, and an error of a few percent is fine. The exact count takes too long. What should the data engineer use?