A nightly JDBC extraction reads a 200-million-row table from an external database and then filters it down to the last three days inside Spark. Network costs are enormous, and the external database is barely coping with the full scans. Which change pushes the filtering work to the source database?
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Correct answer: Wrap the predicate into the dbtable subquery, so the source database applies it before returning rows
Reference: https://docs.databricks.com/aws/en/archive/connectors/jdbc
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Official Answer (B): Wrap the predicate into the dbtable subquery, so the source database applies it before returning rows
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