ducklake-delta-exporter 0.1.1

A utility to export DuckLake database metadata to Delta Lake transaction logs.

🦆 DuckLake Delta Exporter

A Python utility to bridge the gap between DuckLake and Delta Lake by generating Delta-compatible transaction logs directly from DuckLake metadata.

This isn’t your typical general-purpose library. It’s mostly battle-tested with OneLake mounted storage, and while it should work with local filesystems, there’s no support for S3, GCS, or ABFSS .

It doesn’t use the deltalake Python package either. The metadata is handcrafted from scratch — because why not reinvent the wheel for fun and learning?

Goal?
Mostly to annoy DuckDB developers into finally shipping a proper Delta Lake metadata exporter 😎

🔗 Source code on GitHub

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✨ Features

• DuckLake → Delta Sync
  Generates Delta Lake _delta_log/*.json transaction files and Parquet checkpoints from the latest DuckLake state.

• Schema Mapping
  Converts DuckDB types to their Spark SQL equivalents so Delta can understand them without throwing a tantrum.

• Change Detection
  Detects file-level additions/removals since the last export — keeps things incremental and tidy.

• Checkpointing
  Automatically writes Delta checkpoints every N versions (configurable), so readers don’t have to replay the entire log from scratch.

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⚙️ Installation & Usage

Install via pip:

pip install ducklake-delta-exporter

from ducklake_delta_exporter import generate_latest_delta_log

generate_latest_delta_log('/lakehouse/default/Files/meta.db')