DataLane

All stacks · Lakehouse & table formats

Apache Hudi

Incremental upserts, copy-on-write vs merge-on-read, and streaming lakes.

Apache Hudi cover

About Apache Hudi

Apache Hudi is the incremental lake table format: upserts, copy-on-write vs merge-on-read, and timeline-based incremental pulls. It grew up in streaming-into-S3 shops that needed MERGE without a warehouse.

Iceberg and Delta have more mindshare in 2026, but Hudi is still the right answer when incremental consumption and upsert-heavy CDC are the job. Compare formats; do not collect all three.

What you'll learn here

  • Copy-on-write vs merge-on-read and the read/write trade-off
  • Incremental queries vs snapshot queries
  • Compaction, cleaning, and the timeline you must operate
  • Hudi vs Iceberg vs Delta — one writer, one format per table

Frequently asked questions

Should I pick Hudi over Iceberg?

Pick Hudi when incremental ETL from CDC into object storage is the core path and your engine support is Spark-first. Pick Iceberg when multi-engine reads (Snowflake, Trino, Flink) matter more. Do not dual-write.

Is Hudi “streaming”?

It is a table format with incremental pull. You still need a stream processor or Spark streaming job to land events. Hudi does not replace Kafka.

What ops does Hudi add?

Compaction (especially MOR), cleaning old files, and clustering. Skip them and query time grows like any neglected lake table.

New Apache Hudi posts, straight to your inbox

One email a week with our latest tutorials. No spam.

Newsletter signup is not live yet. Use the contact form if you want to be notified.

↑↓ navigate openesc close