Use Delta Lake's Time Travel to Access and Query Historical Data Versions. DATA-ANALYST-ASSOCIATE Practice Questions (Page 2)

Questions 6–10

1. 6application · hard

   A data analyst needs to compare the current state of the `inventory` table with its state from two days ago. The analyst wants to use a single query that returns both the current and historical data. Which approach should the analyst use?

   • AUse a single query with a WHERE clause filtering by a timestamp column.
   • BUse a UNION ALL with one branch using TIMESTAMP AS OF and the other without any time travel clause.
   • CUse a JOIN between the table and itself with VERSION AS OF on both sides.
   • DRun two separate queries: one with TIMESTAMP AS OF for the historical data and one without for the current data.
   Reveal Solution Discussion Select an answer first
2. 7foundation · easy

   Which clause is used to query a Delta table as of a specific timestamp in Databricks SQL?

   • AAT TIMESTAMP
   • BAS OF TIMESTAMP
   • CFOR TIMESTAMP
   • DTIMESTAMP AS OF
   Reveal Solution Discussion Select an answer first
4. 8expert · hard

   A data analyst is troubleshooting a time travel query that fails with a 'file not found' error. The analyst is querying version 8 of the `sales` table. The analyst checks `DESCRIBE HISTORY sales` and confirms version 8 exists. What is the most likely cause of the error?

   • AThe analyst is using the wrong syntax for the time travel query.
   • BThe table was dropped and recreated, resetting the version numbers.
   • CThe analyst is using the wrong table name.
   • DThe VACUUM command was run, which removed the data files for version 8.
   Reveal Solution Discussion Select an answer first
5. 9application · medium

   A data analyst needs to compare the number of rows in the `customers` table between version 3 and version 5. Which approach should the analyst use?

   • AUse a single query with a WHERE clause filtering by version.
   • BRun two separate queries: one with VERSION AS OF 3 and one with VERSION AS OF 5, then compare the row counts.
   • CUse a single query with a JOIN between the table at version 3 and version 5.
   • DUse a single query with a UNION ALL of both versions and count the rows.
   Reveal Solution Discussion Select an answer first
6. 10application · medium

   A data analyst created a temporary view `v_recent_orders` on top of the `orders` table. The analyst wants to use time travel to query the view as of version 5. What should the analyst do?

   • AApply time travel to the underlying `orders` table instead of the view.
   • BUse `SELECT * FROM v_recent_orders VERSION AS OF 5`.
   • CConvert the view to a Delta table before applying time travel.
   • DRecreate the view with a WHERE clause that filters by a version column.
   Reveal Solution Discussion Select an answer first