Given the code:df = spark.

Given the code:

df = spark.read.csv("large_dataset.csv")

filtered_df = df.filter(col("error_column").contains("error"))

mapped_df = filtered_df.select(split(col("timestamp"), " ").getItem(0).alias("date"), lit(1).alias("count"))

reduced_df = mapped_df.groupBy("date").sum("count")

reduced_df.count()

reduced_df.show()

At which point will Spark actually begin processing the data?