DATABRICKS-DEA Question 37

Community Discussion

Written by other learners. Comments can disagree with the marked answer — check the official documentation when in doubt.

• Chose A0

  - Correct answer : A — Increase the `fetchSize` option so each round trip to the source database returns a larger batch of rows, reducing the number of network round trips needed to pull the full result set. A . `fetchSize` directly controls how many rows the JDBC driver buffers per round trip, so raising it from a small default reduces the number of round trips needed and directly addresses the symptom described. B . Adding partitions increases the number of parallel connections used to split a scan by row range; it does not change the row batch size returned per round trip within any one connection. C . Choosing an unindexed `partitionColumn` affects how partition boundaries are computed and can hurt performance, but it has no direct effect on how many rows are returned per network round trip. D . `spark.sql.shuffle.partitions` governs shuffle behavior for wide Spark operations like joins and aggregations after data is loaded; it has no effect on JDBC round-trip batching during the read itself.