Limbo

Limbo is a work-in-progress, in-process OLTP database management system, compatible with SQLite.

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Features

Limbo is an in-process OLTP database engine library that has:

• Asynchronous I/O support on Linux with io_uring
• SQLite compatibility [doc] for SQL dialect, file formats, and the C API
• Language bindings for JavaScript/WebAssembly, Rust, Go, Python, and Java
• OS support for Linux, macOS, and Windows

Getting Started

CLI

Install limbo with:

curl --proto '=https' --tlsv1.2 -LsSf \
  https://github.com/tursodatabase/limbo/releases/latest/download/limbo-installer.sh | sh

Then use the SQL shell to create and query a database:

$ limbo database.db
Limbo v0.0.6
Enter ".help" for usage hints.
limbo> CREATE TABLE users (id INT PRIMARY KEY, username TEXT);
limbo> INSERT INTO users VALUES (1, 'alice');
limbo> INSERT INTO users VALUES (2, 'bob');
limbo> SELECT * FROM users;
1|alice
2|bob

JavaScript (wip)

Installation:

npm i limbo-wasm

Example usage:

import { Database } from 'limbo-wasm';

const db = new Database('sqlite.db');
const stmt = db.prepare('SELECT * FROM users');
const users = stmt.all();
console.log(users);

Python (wip)

pip install pylimbo

Example usage:

import limbo

con = limbo.connect("sqlite.db")
cur = con.cursor()
res = cur.execute("SELECT * FROM users")
print(res.fetchone())

Developing

Build and run limbo cli:

cargo run --package limbo --bin limbo database.db

Run tests:

cargo test

Test coverage report:

cargo tarpaulin -o html

Note

Generation of coverage report requires tarpaulin binary to be installed. You can install it with cargo install cargo-tarpaulin

Tip

If coverage fails with "Test failed during run" error and all of the tests passed it might be the result of tarpaulin bug. You can temporarily set dynamic libraries linking manually as a workaround, e.g. for linux LD_LIBRARY_PATH="$(rustc --print=target-libdir)" cargo tarpaulin -o html.

Run benchmarks:

cargo bench

Run benchmarks and generate flamegraphs:

echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid
cargo bench --bench benchmark -- --profile-time=5

FAQ

How is Limbo different from libSQL?

Limbo is a research project to build a SQLite compatible in-process database in Rust with native async support. The libSQL project, on the other hand, is an open source, open contribution fork of SQLite, with focus on production features such as replication, backups, encryption, and so on. There is no hard dependency between the two projects. Of course, if Limbo becomes widely successful, we might consider merging with libSQL, but that is something that will be decided in the future.

Publications

• Pekka Enberg, Sasu Tarkoma, Jon Crowcroft Ashwin Rao (2024). Serverless Runtime / Database Co-Design With Asynchronous I/O. In EdgeSys ‘24. [PDF]
• Pekka Enberg, Sasu Tarkoma, and Ashwin Rao (2023). Towards Database and Serverless Runtime Co-Design. In CoNEXT-SW ’23. [PDF] [Slides]

Contributing

We'd love to have you contribute to Limbo! Check out the contribution guide to get started.

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Limbo by you, shall be licensed as MIT, without any additional terms or conditions.