Limbo

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

---

Features

• In-process OLTP database engine library
• Asynchronous I/O support with io_uring
• SQLite compatibility (status)
  • SQL dialect support
  • File format support (read-only)
  • SQLite C API
• JavaScript/WebAssembly bindings (wip)

Getting Started

Installing:

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

Limbo is currently read-only. You can either use the sqlite3 program to create a database:

$ sqlite3 database.db
SQLite version 3.42.0 2023-05-16 12:36:15
Enter ".help" for usage hints.
sqlite> CREATE TABLE users (id INT PRIMARY KEY, username TEXT);
sqlite> INSERT INTO users VALUES (1, 'alice');
sqlite> INSERT INTO users VALUES (2, 'bob');

or use the testing script to generate one for you:

pipenv run ./testing/gen-database.py

You can then start the Limbo shell with:

$ cargo run database.db
Welcome to Limbo SQL shell!
> SELECT * FROM users LIMIT 1;
|1|Cody|Miller|mhurst@example.org|525.595.7319x21268|33667 Shaw Extension Suite 104|West Robert|VA|45161|`

Developing

Run tests:

cargo test

Test coverage report:

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.