A simple, portable, high-performance, ACID, embedded key-value store.
redb is written in pure Rust and is loosely inspired by lmdb. Data is stored in a collection of copy-on-write B-trees. For more details, see the design doc
use redb::{Database, Error, ReadableTable, TableDefinition};
const TABLE: TableDefinition<&str, u64> = TableDefinition::new("my_data");
fn main() -> Result<(), Error> {
let db = Database::create("my_db.redb")?;
let write_txn = db.begin_write()?;
{
let mut table = write_txn.open_table(TABLE)?;
table.insert("my_key", &123)?;
}
write_txn.commit()?;
let read_txn = db.begin_read()?;
let table = read_txn.open_table(TABLE)?;
assert_eq!(table.get("my_key")?.unwrap().value(), 123);
Ok(())
}redb is undergoing active development, and should be considered beta quality. The file format is stable, but redb has not been widely deployed in production systems (at least to my knowledge).
- Zero-copy, thread-safe,
BTreeMapbased API - Fully ACID-compliant transactions
- MVCC support for concurrent readers & writer, without blocking
- Crash-safe by default
- Savepoints and rollbacks
To run all the tests and benchmarks a few extra dependencies are required:
cargo install cargo-deny --lockedcargo install cargo-fuzz --lockedapt install libclang-dev
redb has similar performance to other top embedded key-value stores such as lmdb and rocksdb
| redb | lmdb | rocksdb | sled | sanakirja | |
|---|---|---|---|---|---|
| bulk load | 2792ms | 1115ms | 5610ms | 5005ms | 1161ms |
| individual writes | 462ms | 1119ms | 1097ms | 957ms | 662ms |
| batch writes | 2568ms | 2247ms | 1344ms | 1622ms | 2713ms |
| random reads | 988ms | 558ms | 3469ms | 1509ms | 678ms |
| random reads | 962ms | 556ms | 3377ms | 1425ms | 671ms |
| random range reads | 2534ms | 985ms | 6058ms | 4670ms | 1089ms |
| random range reads | 2493ms | 998ms | 5801ms | 4665ms | 1119ms |
| random reads (4 threads) | 344ms | 141ms | 1247ms | 424ms | 266ms |
| random reads (8 threads) | 192ms | 72ms | 673ms | 230ms | 620ms |
| random reads (16 threads) | 131ms | 47ms | 476ms | 148ms | 3500ms |
| random reads (32 threads) | 118ms | 44ms | 412ms | 129ms | 4313ms |
| removals | 2184ms | 784ms | 2451ms | 2047ms | 1344ms |
Source code for benchmark here. Results collected on a Ryzen 5900X with Samsung 980 PRO NVMe.
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