Dynamic Partition Overwrite Mode

How can we overwrite only the partitions modified in the current batch without deleting the entire historical dataset?

Expert⏱ 3 Minutes⭐ 820 XP

🤔 THE QUESTION

How can we overwrite only the partitions modified in the current batch without deleting the entire historical dataset?

💡 WHAT IS IT?

Setting partitionOverwriteMode to 'dynamic' ensures Spark only replaces directories matching the incoming batch partition keys.

🎯 WHAT IS IT USED FOR?

Idempotent daily backfills and updates in partitioned lakehouse tables without risk of wiping full table history.

💻 EXAMPLE

spark.conf.set("spark.sql.sources.partitionOverwriteMode", "dynamic")
df_daily_batch.write.partitionBy("sale_date").mode("overwrite").parquet("s3://lakehouse/gold/daily_sales/")

🎯 Mission Objectives

Practice typing production-grade PySpark code for Dynamic Partition Overwrite Mode.

✓ dynamic partitionOverwriteMode
✓ Targeted partition replacement
✓ Safe backfill execution

🚀 Start Mission

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