Deletion vectors

Deletion vectors is a Databricks data engineering capability, introduced October 2023.

A merge-on-read trick for Delta Lake and Iceberg tables - a delete marks rows in metadata rather than rewriting whole data files, and reads subtract the marked rows at query time.

• The speed comes from not doing the work. A delete that would have rewritten a gigabyte file instead writes down which rows to skip, and the file is left exactly where it was. 🔗
• Enabling them on a materialized view or streaming table is a one-way door - you can switch the feature back off, but the table protocol can never be downgraded again. 🔗
• On Delta they are something you turn on, but every Apache Iceberg v3 table gets them whether you asked or not. 🔗

Category

Data engineering

Introduced

October 2023🔗

Also known as

deletion vector, merge-on-read deletes, delta.enableDeletionVectors

Verified

2026-09-17