FnckSQL is a lightweight, LSM KV-based SQL Database Management System (DBMS) created by individual developers as a hobby project. The core objective of FnckSQL is to demonstrate that anyone can write a database, even if the primary author cannot find a job in the industry. The project name and its irreverent tone reflect this sentiment, symbolizing a defiant stance toward the "beautiful" database industry.

FnckSQL offers a variety of features typically found in more mature SQL databases, including:

Core Features

LSM KV-based Storage Engine

FnckSQL utilizes a Log-Structured Merge (LSM) tree as its storage engine, providing efficient write performance and supporting high throughput for database operations.

SQL Interface

FnckSQL supports a comprehensive SQL interface with capabilities such as projections, filters, joins, aggregates, and transactions. This makes it a fully functional SQL database, suitable for learning and experimentation.

ORM Mapping

FnckSQL includes Object-Relational Mapping (ORM) features, enabling the use of Rust structs directly within the database:

#[derive(Default, Debug, PartialEq)]
struct MyStruct {
  c1: i32,
  c2: String,
    MyStruct, (
        c1: i32 => |inner: &mut MyStruct, value| {
            if let DataValue::Int32(Some(val)) = value {
                inner.c1 = val;
        c2: String => |inner: &mut MyStruct, value| {
            if let DataValue::Utf8(Some(val)) = value {
                inner.c2 = val;

User-Defined Functions

Developers can create user-defined functions to extend the functionality of the database:

function!(TestFunction::test(LogicalType::Integer, LogicalType::Integer) -> LogicalType::Integer => |v1: ValueRef, v2: ValueRef| {
    let plus_binary_evaluator = EvaluatorFactory::binary_create(LogicalType::Integer, BinaryOperator::Plus)?;
    let value = plus_binary_evaluator.binary_eval(&v1, &v2);
    let plus_unary_evaluator = EvaluatorFactory::unary_create(LogicalType::Integer, UnaryOperator::Minus)?;
let fnck_sql = DataBaseBuilder::path("./data")

Optimizer and Execution

FnckSQL features both a Rule-Based Optimizer (RBO) and a Cost-Based Optimizer (CBO). For execution, it uses the Volcano model and supports LuaJIT for code generation.

MVCC Transactions

FnckSQL implements Multi-Version Concurrency Control (MVCC) with support for optimistic transactions, ensuring data consistency and isolation across multiple transactions.

Indexing and Query Support

FnckSQL supports various index types, including primary, unique, normal, and composite indexes. It also offers a full range of SQL query capabilities, such as:

  • Select: With SeqScan and IndexScan
  • Where, Distinct, Alias
  • Aggregation: count(), sum(), avg(), min(), max()
  • Subqueries: Select, From, Where
  • Join: Inner, Left, Right, Full, Cross
  • Group By, Having, Order By, Limit
  • DDL: Create Table, Index, Drop Table, Add/Drop Column, Truncate
  • DML: Insert, Update, Delete

Docker Support

FnckSQL provides Docker images for easy deployment:

docker pull kould23333/fncksql:latest

To build from source:

git clone https://github.com/KipData/FnckSQL.git
cd FnckSQL
docker build -t kould23333/fncksql:latest .

To run the Docker container:

docker run -d \
--name=fncksql \
-p 5432:5432 \
--restart=always \
-v fncksql-data:/fnck_sql/fncksql_data \
-v /etc/localtime:/etc/localtime:ro \

Similar Projects



  1. Home
  2. Learn Rust
  3. Get Started
  4. Practice Rust
  5. Challenges
  6. Tutorials
  7. Blog
  8. Open source
  9. Learn Gleam


  1. GitHub
  2. X


  1. Privacy Policy
  2. Terms of Service