While validating a silver notebook, an engineer joins two small bronze tables to check key overlap before promoting the pipeline: ```python payments = spark.read.table("catalog.fin.bronze_payments") # 3 rows: txn 101, 202, 303 refunds = spark.read.table("catalog.fin.bronze_refunds") # 4 rows: txn 202, 303, 404, 505 joined = payments.join(refunds, "txn_id", "inner") print(joined.count()) ``` What number is printed, and why?
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Correct answer: 2 — only the txn_id values present in both tables survive the inner join
Reference: https://docs.databricks.com/aws/en/pyspark/reference/functions
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02 — The Myelin Layer · Canonical Discussion
Where the exam tries to trick you — and how those who passed solved it.
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Official Answer (A): 2 — only the txn_id values present in both tables survive the inner join
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