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PYSPARK • LESSON 222

Business Key Deduplication with dropDuplicates()

How can we deduplicate a dataset based only on specific business keys like customer_id and transaction_date?

Advanced3 Minutes810 XP
🤔 THE QUESTION

How can we deduplicate a dataset based only on specific business keys like customer_id and transaction_date?

💡 WHAT IS IT?

dropDuplicates(subset=[...]) retains the first encountered row for each unique combination of specified key columns.

🎯 WHAT IS IT USED FOR?

Enforcing unique primary key constraints when non-key metadata columns may have minor variations.

💻 EXAMPLE
df_deduped = df.dropDuplicates(subset=["customer_id", "transaction_date"])

🎯 Mission Objectives

Practice typing production-grade PySpark code for Business Key Deduplication with dropDuplicates().

  • dropDuplicates() with subset
  • Primary key constraint enforcement
  • Key-based deduplication