Beginning Apache Spark 3 Pdf -

squared_udf = udf(squared, IntegerType()) df.withColumn("squared_val", squared_udf(df.value))

spark.stop()

General rule: 2–3 tasks per CPU core.

query.awaitTermination() Structured Streaming uses checkpointing and write‑ahead logs to guarantee end‑to‑end exactly‑once processing. 6.4 Event Time and Watermarks Handle late data efficiently: beginning apache spark 3 pdf