10fd8bb234
This PR fixes queries like:
```sql
SELECT count(*) FROM users WHERE ((age > 25 OR age < 18) AND (city = 'Boston' OR state = 'MA'));
```
Previously we would return `7516` rows instead of `146`, due to
disregarding the final `AND` from within the nested `OR` conditions,
unconditionally short circuiting when a TRUE is found in an OR
expression without any surrounding relevant context.
or:
```sql
SELECT * FROM users WHERE (((age > 18 AND city = 'New Mario') OR age = 92) AND city = 'Lake Paul');
```
Previously we would incorrectly return the top row:
```
9984|Leah|Russell|..|..|6733 Weber Crossing|New Mario|SC|57707|78
9989|Timothy|Harrison|..|..|782 Wright Harbors|Lake Paul|ID|52330|92
```
Added localized jump targets for OR expressions within AND blocks to
prevent premature short-circuiting and `parent operator` to condition
metadata to trigger them.
If parent operator should instead be another function param on
`translate_conditional_expr`, instead of a field in condition_metadata,
let me know and I can change it.
EDIT: sorry I realize I should have included the other cleanup changes
in a different PR. I will fix this after work
Reviewed-by: Jussi Saurio <kacperoza@gmail.com>
Closes #633
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 on Linux with
io_uring - SQLite compatibility (status)
- SQL dialect support
- File format support
- SQLite C API
- JavaScript/WebAssembly bindings (wip)
- 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.