Design and Implement Scalable Data Models Using Delta Lake to Manage Large Datasets. DATA-ENGINEER-PROFESSIONAL Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   A data engineer is designing a Delta Lake table that will store billions of rows of IoT sensor data. The table will be frequently queried with filters on the `device_id` and `timestamp` columns. Which table design choice is most likely to improve query performance?

   • APartition by both `device_id` and `timestamp`
   • BDo not partition; use Z-order on both columns
   • CPartition by `device_id` and Z-order by `timestamp`
   • DPartition by `timestamp` and Z-order by `device_id`
   Reveal Solution Discussion Select an answer first
2. 17expert · hard

   A company has a Delta Lake table that stores financial transactions. They need to retain data for 7 years for regulatory compliance, but they also need to keep the table performant. The table receives daily updates and is queried by auditors. They run VACUUM with a retention period of 7 days. What is the best approach to balance retention and performance?

   • AKeep all data and rely on time travel for historical queries
   • BRun VACUUM with a retention period of 7 years to keep all files
   • CUse `OPTIMIZE` daily to compact files and retain all data
   • DPartition the table by year and archive old partitions to cold storage
   Reveal Solution Discussion Select an answer first
4. 18foundation · easy

   A data engineer needs to query a Delta Lake table as it existed exactly two hours ago to investigate a data quality issue. Which feature allows this without restoring the table?

   • AChange data feed
   • BZ-ordering
   • CSchema evolution
   • DTime travel
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   Which Delta Lake operation is used to physically delete old files that are no longer referenced by the table and are older than a specified retention period?

   • AMERGE
   • BOPTIMIZE
   • CZORDER BY
   • DVACUUM
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A company has a Delta Lake table that stores historical sensor data. They need to retain data for 30 days for compliance, but they also need to keep the table performant. They run nightly jobs that update the table. What should they do to manage the table lifecycle?

   • ARun VACUUM with a retention period of 30 days to clean up old files
   • BDelete rows older than 30 days and then run VACUUM with a retention period of 7 days
   • CRun OPTIMIZE daily to compact files and retain all data
   • DUse time travel to query only the last 30 days of data
   Reveal Solution Discussion Select an answer first