delta-fusion 1.1.3

High-performance Delta Lake query engine for Python

deltaFusion

High-performance Delta Lake query engine for Python, powered by Rust.

Overview

deltaFusion provides SQL query capabilities over Delta Lake tables using DataFusion as the query engine. Data is transferred via zero-copy Apache Arrow for maximum performance.

Key Features

• SQL Queries: Full SQL support via DataFusion
• Zero-Copy Transfer: Arrow-based data exchange with Python (no serialization overhead)
• Time Travel: Query specific table versions
• Storage Support: Local filesystem and S3-compatible storage
• GIL Release: Python threads remain active during Rust operations

Installation

# From source (requires Rust toolchain and maturin)
pip install maturin
maturin develop --release

Quick Start

from delta_fusion import DeltaEngine

# Create engine
engine = DeltaEngine()

# Register a Delta table
engine.register_table("sales", "/path/to/delta/table")

# Query with SQL (returns PyArrow RecordBatches)
batches = engine.query("SELECT * FROM sales WHERE year = 2024")

# Convert to pandas
import pyarrow as pa
table = pa.Table.from_batches(batches)
df = table.to_pandas()

# Or get results as list of dicts (for small datasets)
rows = engine.query_to_dicts("SELECT * FROM sales LIMIT 10")

S3 Storage

# Option 1: Environment variables
# AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION

# Option 2: Explicit configuration
engine = DeltaEngine({
    "aws_access_key_id": "...",
    "aws_secret_access_key": "...",
    "aws_region": "us-east-1",
    "aws_endpoint": "http://localhost:9000",  # For MinIO
    "aws_allow_http": True
})

engine.register_table("data", "s3://bucket/delta-table")

Time Travel

# Query a specific version
engine.register_table("sales", "/path/to/table", version=5)

# Get table metadata
info = engine.table_info("/path/to/table")
print(f"Version: {info['version']}, Files: {info['num_files']}")

Development

# Build for development
maturin develop

# Run Rust tests
cargo test --no-default-features

# Run Python tests
pytest

# Check and format
cargo check
cargo clippy
cargo fmt

Architecture

src/
├── lib.rs       # Module entry point
├── config.rs    # Storage configuration
├── error.rs     # Error types
├── engine.rs    # DeltaEngine (DataFusion integration)
└── python.rs    # PyO3 bindings

python/delta_fusion/
├── __init__.py  # Python API
└── __init__.pyi # Type stubs

License

This project is licensed under the MIT License - see the LICENSE file for details.