Trino Lance Connector

A Trino connector for reading and writing Lance format data. This connector allows Trino to query Lance datasets and fragments directly.

Features

• Lance Dataset Support: Read data from Lance datasets
• Lance Fragment Support: Read data from individual Lance fragments
• Schema Discovery: Automatic schema detection from Lance metadata
• Column Projection: Efficient column selection and projection

Building

To build the connector:

mvn clean package

Installation

1. Build the connector using Maven
2. Copy the generated JAR file to your Trino plugins directory
3. Configure the connector in your Trino catalog properties

Configuration

Create a catalog properties file (e.g., etc/catalog/lance.properties):

connector.name=lance
# Add any additional configuration properties here

Usage

Once configured, you can query Lance data using SQL:

-- Query a Lance dataset
SELECT * FROM lance.default.my_dataset;

-- Query specific columns
SELECT id, name, value FROM lance.default.my_dataset WHERE value > 100;

Development Guide

Project Structure

Everything in this repository apart from the plugin/trino-lance mimics the layout of the Trino project. For example, the root pom file is a copy of the Trino root pom file with exactly the same content. We periodically upgrade the Trino version to stay up to date with the latest Trino features.

Build

Build project:

./mvnw install