Databricks · Databricks Data Analyst Associate
Delta history, predictive optimization, and liquid clustering
Databricks Data Analyst Associate · Lesson 12 of 18 · 1:26:35
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In this lesson
Prepare for the Databricks Certified Data Analyst Associate exam. In this lesson: auditing with DESCRIBE HISTORY and comparing versions with EXCEPT, predictive optimization (OPTIMIZE, VACUUM, and ANALYZE on managed tables), liquid clustering and CLUSTER BY AUTO, and fixing queries that return wrong results. Includes three original practice questions.
Preview the topics
- The analyst thinks that the nightly load wrote the same data twice into the gold sales table. Where can the analyst see which operations changed the table last night, and how many rows each one wrote?
- Analysts filter the managed rentals table by different columns from month to month, and nobody wants to maintain clustering keys by hand. Predictive optimization is enabled. What should be set on the table?
- A query computes a conversion rate for each store: rentals divided by visits. It fails with a division by zero error, because two new stores have no visits yet. How should the analyst fix it?