Utilize Delta Lake to Audit and View History, Validate Results, and Compare Historical Results or Trends. DATA-ANALYST-ASSOCIATE Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   In the output of DESCRIBE HISTORY, what does the 'version' column represent?

   • AThe unique identifier of the user who performed the operation
   • BThe sequential version number of the table after the operation
   • CThe version of the Delta Lake software used to perform the operation
   • DThe number of rows affected by the operation
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2. 12expert · hard

   A data analyst is investigating a data quality issue in the `product` Delta table. The analyst suspects that a specific update operation corrupted some data. The analyst wants to identify the exact version where the corruption was introduced and then examine the data before and after that version. Which sequence of actions should the analyst take?

   • ARun DESCRIBE HISTORY product to identify the update version, then query the table using VERSION AS OF for the versions before and after that update.
   • BRun OPTIMIZE product to compact files, then query the current data.
   • CRun VACUUM product to clean up old files, then query the current data.
   • DRun SELECT * FROM product VERSION AS OF 0 and compare it to the current data.
   Reveal Solution Discussion Select an answer first
4. 13application · medium

   A data analyst runs DESCRIBE HISTORY on the `sales` Delta table and sees a version with operation 'DELETE' and operationParameters containing 'predicate' = '["(date = \"2024-01-01\")"]'. What does this tell the analyst about the operation?

   • AThe operation deleted all rows where the date column equals '2024-01-01'.
   • BThe operation added new rows with the date '2024-01-01'.
   • CThe operation updated the date column to '2024-01-01' for all rows.
   • DThe operation deleted the entire table.
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5. 14foundation · easy

   How can Delta Lake's audit capabilities help validate the correctness of a query result?

   • ABy comparing the result to the table's state at a known-good historical version
   • BBy preventing any incorrect results from being returned
   • CBy showing the exact query plan used
   • DBy automatically fixing any errors in the query
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6. 15foundation · easy

   What type of information does DESCRIBE HISTORY return for a Delta table?

   • AThe exact SQL query text used in the last query against the table
   • BDetails about each operation, including version, timestamp, operation type, and user
   • COnly the current schema and partitioning information
   • DA list of all files currently in the table's storage location
   Reveal Solution Discussion Select an answer first