Delta Lake
by Delta Lake project (Linux Foundation; created by Databricks) · Specification · also known as delta-rs, deltalake
Open table format with a transaction log over Parquet files, created by Databricks and hosted by the Linux Foundation, with Spark, Rust and Python implementations
Overview
Delta Lake is an open-source table format that layers an ordered transaction log (the _delta_log directory of JSON and checkpoint files) over Parquet data files to provide ACID transactions, schema enforcement and evolution, time travel and efficient upserts and deletes on object storage. It was created by Databricks, is hosted by the Linux Foundation under the Apache 2.0 license, and is the native table format of the Databricks platform, where most of its advanced features first appear. Besides the Spark connector, the delta-rs Rust library and its Python package deltalake allow reading and writing tables without a JVM, and Delta Kernel provides a connector library for other engines. Polars, DuckDB, Trino, Flink, pandas (via deltalake) and several warehouses read Delta tables; UniForm can expose a Delta table with Iceberg-compatible metadata.
Delta Lake suits teams on Databricks or Spark who need reliable incremental pipelines over a lake, and Python users who want transactional writes to Parquet from a laptop through delta-rs. Compared with Iceberg, governance of the project remains closely tied to one vendor, catalog integration is less standardized, and some features depend on the engine implementing the corresponding protocol version.
Capabilities
- Transaction log providing ACID commits over Parquet
- Schema enforcement and evolution
- Time travel and table history
- MERGE, UPDATE and DELETE operations
- delta-rs Rust/Python implementation without a JVM
- UniForm metadata for Iceberg readers
Typical workflows
- Incremental ETL with merges on Databricks or Spark
- Transactional Parquet writes from Python with deltalake
- Reading lake tables from Polars or DuckDB
Strengths
- Simple log-based design on plain object storage
- Mature Spark integration
- Lightweight Rust and Python access
Limitations
- Feature set advances first on Databricks
- Protocol versions must be supported by each reader
- Catalog integration less standardized than Iceberg's REST catalog
Prerequisites
- Object or file storage plus Spark or the deltalake Python package
Who it is for
- Spark and Databricks users
- Python data engineers needing transactional Parquet
Alternatives & comparison
- Apache Iceberg
Open table format for data lakes that adds ACID snapshots, schema and partition evolution and time travel over Parquet, ORC or Avro files
Open sourceOpen source - Apache Parquet
Open columnar file format for analytical data with compression, encodings and statistics, readable by nearly every data engine and library
Open sourceOpen source - Apache Spark
Distributed data processing engine with DataFrame and SQL APIs in Python, Scala, Java and R, plus structured streaming and MLlib
Open sourceOpen source - DuckDB
In-process analytical SQL database that queries Parquet, CSV and Arrow data directly from Python, R, Node or the CLI
Open sourceOpen source
Sources & verification
Primary sources consulted for this record. Claims are tied to the fields each source supports; the automated link checker re-verifies every URL on a schedule.
- LicenseDelta Lake LICENSE.txt (Apache 2.0)checked Nov 1, 2026
https://github.com/delta-io/delta/blob/master/LICENSE.txt
Supports: license_spdx, source_model
- Official documentationchecked Nov 1, 2026
- Official sitechecked Nov 1, 2026
- Repositorychecked Nov 1, 2026
- Confidence
- High
- Reviewed
- Nov 1, 2026
- Links
- Verified · Nov 2, 2026
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