A Delta table was created with Liquid Clustering using `CLUSTER BY (region, order_date)`. Usage has shifted: most queries now filter by `customer_id`, and region filters are rare. The table holds several years of data that must not be rewritten wholesale. How can the clustering keys be adapted?

1. A. They cannot be changed: clustering keys are fixed at table creation, so the team must copy the data into a new table clustered by the new keys 💬 A
2. B. Run OPTIMIZE orders ZORDER BY (customer_id) to layer ZORDER columns on top of the existing clustering 💬 B
3. C. Recreate the table with CREATE OR REPLACE TABLE orders CLUSTER BY (region, customer_id) and reinsert all rows during the next maintenance window 💬 C
4. D. Run ALTER TABLE orders CLUSTER BY (region, customer_id): new keys apply to new writes, and OPTIMIZE re-clusters incrementally ✓ D

Reveal answer

Correct answer: Run ALTER TABLE orders CLUSTER BY (region, customer_id): new keys apply to new writes, and OPTIMIZE re-clusters incrementally

Reference: https://docs.databricks.com/aws/en/tables/clustering