Counting Rows with count()

How do we calculate total order volume across an entire dataset using the count() aggregate function?

Intermediate⏱ 2 Minutes⭐ 350 XP

🤔 THE QUESTION

How do we calculate total order volume across an entire dataset using the count() aggregate function?

💡 WHAT IS IT?

count('*') calculates the total number of records in the DataFrame as a distributed aggregation.

🎯 WHAT IS IT USED FOR?

Batch reconciliation, logging dataset size metrics, and validating completeness against source systems.

💻 EXAMPLE

from pyspark.sql.functions import count

df.select(count("*").alias("total_orders")).show()

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