DuckDB

DuckDB is an in-process SQL OLAP database management system designed for speed and ease of use. It runs directly within your application, eliminating the need for a separate server and complex setup. It's simple to install and deploy, with zero external dependencies and a single binary file. DuckDB is built for analytical queries, using a columnar-vectorized query engine to process data at high speeds, even on datasets larger than available memory.

Key features include:

• Portability: Runs on Linux, macOS, Windows, and more, with idiomatic APIs for Python, R, Java, and Node.js.
• Rich SQL Dialect: Offers extensive SQL capabilities, including direct querying of files.
• Versatile Data Handling: Read and write various formats like CSV, Parquet, and JSON directly from local files or remote endpoints like S3.
• Extensibility: Supports custom extensions for new data types, functions, and file formats.
• Free and Open-Source: Available under the permissive MIT License.