Save Data to Persistent Tables While Applying Sorting and Partitioning to Optimize Data Retrieval. ASSOCIATE-DEVELOPER-APACHE-SPARK Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   What is the default behavior of saveAsTable when the table already exists?

   • AIt appends the new data to the existing table.
   • BIt throws an error if the table already exists.
   • CIt ignores the operation if the table exists.
   • DIt overwrites the existing table.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A retail company stores daily sales transactions in a Delta table. Analysts frequently run queries that filter on the `order_date` column and aggregate sales by `store_id`. The data volume is large, and query performance has degraded. You need to persist the DataFrame as a managed table that minimizes the amount of data scanned for these common queries. Which approach should you use?

   • Adf.write.option("path", "/mnt/sales").saveAsTable("sales")
   • Bdf.write.bucketBy(16, "store_id").saveAsTable("sales")
   • Cdf.write.partitionBy("order_date").saveAsTable("sales")
   • Ddf.write.sortBy("order_date").saveAsTable("sales")
   Reveal Solution Discussion Select an answer first
4. 8expert · hard

   A telecommunications company stores call detail records in a table. Queries often filter on `call_date` and `region`, and also aggregate by `call_type`. The table is currently partitioned by `call_date` only. You notice that queries filtering on both `call_date` and `region` still scan many partitions. What should you do to improve performance?

   • AAdd `region` as a second partition column using `partitionBy("call_date", "region")`
   • BReplace `call_date` partitioning with `region` partitioning
   • CSort the table by `region` within each `call_date` partition
   • DBucket the table by `region`
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   Which strategy is most effective for improving the performance of a query that frequently filters on a specific column?

   • ACaching the table in memory.
   • BBucketing the table by that column.
   • CSorting the table by that column.
   • DPartitioning the table by that column.
   Reveal Solution Discussion Select an answer first
6. 10foundation · easy

   What does the sortBy clause do when saving a DataFrame as a table?

   • AIt buckets the table into a fixed number of buckets.
   • BIt partitions the table by the specified columns.
   • CIt sorts the entire table globally.
   • DIt sorts data within each partition.
   Reveal Solution Discussion Select an answer first