SlothDB

Judgement

What it is

Building block

What it does

An embedded SQL engine in C++20 that queries Parquet, CSV, JSON, Arrow, Avro, SQLite and Excel files in-process, in the style of DuckDB. It has Python and WebAssembly packages and an optional local model for turning questions into SQL.

Adopt it when

You want to study or experiment with a small embedded analytical engine and can tolerate early-stage behavior.

Watch out

The author calls it a learning exercise and tells readers to treat its performance numbers as anecdotal, and the last commit was in June.

Ready for

Experimental

Runs as

Library and command line

Built with

C++, Python and WebAssembly

How established

Young: started 6 months ago, latest release v0.2.7.

What the license allows

You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-06 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: SlothDB → LLVM project → runs on a microchip

How compilers were built, back to punched paper tape

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