rrrdb: RDB built on top of RocksDB written in Rust

Under construction

How to Use

let rrrdb = RrrDB::new(path)
rrrdb.execute("test_db", "CREATE TABLE users (id integer, name varchar)").unwrap(); // should handle properly
rrrdb.execute("test_db", "INSERT INTO users VALUES (1, 'Alice')").unwrap();
rrrdb.execute("test_db", "INSERT INTO users VALUES (2, 'Bob')").unwrap();
let result = rrrdb.execute("test_db", "SELECT name FROM users WHERE id = 2").unwrap();
result == 
    OkDBResult::SelectResult(ResultSet::new(
        vec![
            Record::new(vec![
                FieldValue::Text("Bob".to_string()),
            ]),
        ],
        ResultMetadata::new(vec![
            FieldMetadata::new("name", "varchar")
        ])
    ))

Feature

SQL

Suported SQLs are like:

CREATE TABLE users (id integer, name varchar)
INSERT INTO users VALUES (1, 'Alice')
SELECT * FROM users
SELECT name FROM users WHERE id = 2

So, I'd say it's a tiny subset of SQL supported.

Supported Type

Basically, Int and String are supported. Boolean will be there soon, hopefully.

Design

Layered

SQL layer
- tokenize and parse given SQLs
Planner
- compile a given SQL into a Plan that represents how to fetch data from storage layer, which is RocksDB
Executor
- fetch data based on a given Plan
Storage
- can be considered RocksDB wrapper
- get a record by a key
- get a iterator on a ColumnFamily
- put a record with a key

Storage Layer

Use RocksDB as a backend storage layer to persist actual data. RocksDB is a Key-Value store, and RrrDB is row-oriented database on top of RocksDB.

Using ColumnFamily of RocksDB to store:

Metadata
- ColumnFamily name: "metadata"
- key: database name, value: database schema(JSON)
Database
- not in used
Table
- Stores records in a particular table
- ColumnFamily name: <database_name>_<table_name>
- key: primary key, value: record(JSON)

These are obviously too naive, but works.

License

Apache License 2.0

petitviolet / rrrdb