bf2e254a21
Built on top of, and currently targets, #350, _not_ main Closes #365 Examples: ``` limbo> explain select u.first_name, p.name from users u join products p on u.id = p.id order by u.id; addr opcode p1 p2 p3 p4 p5 comment ---- ----------------- ---- ---- ---- ------------- -- ------- 0 Init 0 15 0 0 Start at 15 1 OpenReadAsync 0 2 0 0 table=u, root=2 2 OpenReadAwait 0 0 0 0 3 OpenReadAsync 1 3 0 0 table=p, root=3 4 OpenReadAwait 0 0 0 0 5 RewindAsync 0 0 0 0 6 RewindAwait 0 14 0 0 Rewind table u 7 RowId 0 1 0 0 r[1]=u.rowid 8 SeekRowid 1 1 12 0 if (r[1]!=p.rowid) goto 12 9 Column 0 1 2 0 r[2]=u.first_name 10 Column 1 1 3 0 r[3]=p.name 11 ResultRow 2 2 0 0 output=r[2..3] 12 NextAsync 0 0 0 0 13 NextAwait 0 7 0 0 14 Halt 0 0 0 0 15 Transaction 0 0 0 0 16 Goto 0 1 0 0 ``` ``` limbo> explain select * from users where age > 80 order by age limit 5; addr opcode p1 p2 p3 p4 p5 comment ---- ----------------- ---- ---- ---- ------------- -- ------- 0 Init 0 23 0 0 Start at 23 1 OpenReadAsync 0 2 0 0 table=users, root=2 2 OpenReadAwait 0 0 0 0 3 OpenReadAsync 1 274 0 0 table=age_idx, root=274 4 OpenReadAwait 0 0 0 0 5 Integer 80 1 0 0 r[1]=80 6 SeekGT 1 22 1 0 7 DeferredSeek 1 0 0 0 8 RowId 0 2 0 0 r[2]=users.rowid 9 Column 0 1 3 0 r[3]=users.first_name 10 Column 0 2 4 0 r[4]=users.last_name 11 Column 0 3 5 0 r[5]=users.email 12 Column 0 4 6 0 r[6]=users.phone_number 13 Column 0 5 7 0 r[7]=users.address 14 Column 0 6 8 0 r[8]=users.city 15 Column 0 7 9 0 r[9]=users.state 16 Column 0 8 10 0 r[10]=users.zipcode 17 Column 0 9 11 0 r[11]=users.age 18 ResultRow 2 10 0 0 output=r[2..11] 19 DecrJumpZero 12 22 0 0 if (--r[12]==0) goto 22 20 NextAsync 1 0 0 0 21 NextAwait 1 7 0 0 22 Halt 0 0 0 0 23 Transaction 0 0 0 0 24 Integer 5 12 0 0 r[12]=5 25 Goto 0 1 0 0 ``` Closes #366
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
- 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 work-in-progress so it's recommended that you either use the sqlite3 program to create a test 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:
$ limbo 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.