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PYSPARK โ€ข LESSON 185

Change Data Capture (CDC) Incremental Processing

How do we query incremental database CDC feeds using watermark timestamps to avoid full-table re-scans?

Productionโฑ 2 Minutesโญ 1300 XP
๐Ÿค” THE QUESTION

How do we query incremental database CDC feeds using watermark timestamps to avoid full-table re-scans?

๐Ÿ’ก WHAT IS IT?

Filtering parquet CDC logs for records where ingestion_timestamp exceeds the last high watermark.

๐ŸŽฏ WHAT IS IT USED FOR?

High-frequency incremental ETL pipelines processing only new inserts and updates from operational DBs.

๐Ÿ’ป EXAMPLE
from pyspark.sql.functions import col

incremental_df = spark.read.parquet("raw/cdc_feed") \
    .filter(col("ingestion_timestamp") >= last_watermark)

๐ŸŽฏ Mission Objectives

Practice typing production-grade PySpark code for Change Data Capture (CDC) Incremental Processing.

  • โœ“ Read raw CDC log feed
  • โœ“ Filter on high watermark timestamp
  • โœ“ Process incremental database deltas