Build Your Own Database Engine

This is an educational relational database engine used in Carnegie Mellon University's database systems course. Students learn internals by implementing core components of a working database, including storage, indexing, concurrency control, and crash recovery. The system covers key database architecture: a B+ tree index for fast key-based lookups and range scans, a disk-oriented buffer pool that caches pages from disk, an iterator-based query execution model that composes physical operators, page-based storage for records, two-phase locking for coordinating concurrent transactions, and write

MiniOB is an open-source educational relational database kernel designed for learning the internals of database systems. It implements a dual-engine storage architecture combining B+ Tree and LSM-Tree, supports SQL parsing and query execution, and provides transactional processing with multi-version concurrency control. The system communicates with clients using the MySQL wire protocol and includes a vector database extension for storing and querying high-dimensional vectors. The project distinguishes itself through its comprehensive coverage of core database concepts in a single, learnable c

This project is an educational implementation of a relational database engine written in C. It functions as a SQLite clone, demonstrating the internal mechanics of a database system through a C-based systems project that focuses on manual memory management and file I/O. The engine is distinguished by its use of a bytecode virtual machine, which executes database operations by compiling SQL statements into low-level instructions. It utilizes a B-tree database engine to organize records in a balanced tree structure, ensuring efficient insertion, search, and range scanning. The system covers co

Mini-LSM is an educational storage engine and key-value database library designed to demonstrate the implementation of log-structured merge-tree architecture. It serves as a pedagogical resource for understanding how to build high-performance storage systems from the ground up, focusing on the mechanics of persistent data structures and disk-based storage. The project provides a functional framework for managing data through memory-to-disk flushing and multi-version concurrency control. It distinguishes itself by implementing snapshot-based isolation, which allows for consistent views of the

MapDB is an embedded database engine and disk-backed collection library that stores Java collections on disk or off-heap. It functions as a local data processing engine designed to handle datasets that exceed available physical RAM. The project utilizes off-heap data storage to eliminate garbage collection overhead and employs disk overflow caching to balance memory and disk usage. It provides specialized utilities for filtering and analyzing large volumes of local data on a single machine. The system ensures data integrity through ACID-compliant transactions and multi-version concurrency co

SlateDB is a cloud-native key-value store and distributed database engine that utilizes a log-structured merge-tree architecture. It serves as a transactional storage layer designed to persist data directly to cloud object storage. The engine differentiates itself by optimizing read performance for remote storage through the use of bloom filters and multi-level block caching. It employs a single-writer multi-reader model and provides the ability to create zero-copy clones via copy-on-write checkpointing. The system supports atomic transactions, range queries, and snapshot-based concurrency c

LiteDB is a serverless, embedded NoSQL document database for .NET applications. It persists data into a single portable file, functioning as a BSON data store that resides within the application process rather than running as a separate server. The system is ACID compliant, utilizing write-ahead logging to ensure atomic, consistent, isolated, and durable transactions. It includes built-in encryption to provide secure local data storage and protect files on disk from unauthorized access. The project covers object-document mapping to convert classes into document formats, indexed search capabi

redb is an embedded key-value store and ACID-compliant storage engine. It functions as a persistent storage system for saving and retrieving data as key-value pairs within a tree structure. The engine is built as an MVCC transactional database, utilizing multi-version concurrency control to manage simultaneous reads and writes without blocking. It employs a single-writer multi-reader model to ensure data consistency while allowing multiple threads to access the store. The system provides persistent state management and atomic transaction management to prevent data corruption during crashes.

Sled is an embedded key-value store and ACID-compliant database designed for high-performance data persistence. It functions as a log-structured storage engine that organizes data using B+ trees to support efficient range queries and prefix scans. The engine implements a zero-copy data store model, utilizing epoch-based reclamation to provide direct references to cached values without memory allocations. It distinguishes itself through a combination of write-ahead logging, page cache optimizations to reduce write amplification on flash storage, and serializable transactions for atomic multi-k

Pebble is an embedded key-value storage engine written in Go, designed as a library that provides durable, write-optimized data persistence directly within applications. It organizes data using a log-structured merge-tree (LSM-tree) structure, where writes are first buffered in an in-memory skiplist memtable and persisted to a write-ahead log before being flushed to block-based SSTable files on disk. The engine supports atomic batch commits, configurable write synchronization, and automatic background compaction that merges and rewrites sorted runs to reclaim space and maintain read performanc

Bolt is a single-file embedded key-value store for Go applications. It is an ACID transactional database that organizes data in B+trees on disk to provide efficient sorted key retrieval and range scans. The system uses a memory-mapped model to map the database file directly into the process address space for fast random-access reads. The project distinguishes itself through a multi-version concurrency control architecture that allows multiple simultaneous readers to access a consistent snapshot of data without blocking a writer. It employs a single-writer multi-reader locking model and uses a

bbolt is an ACID-compliant embedded key-value store for Go applications. It persists all data in a single memory-mapped file on disk, organizing information using B+ trees to facilitate sorted key iteration and efficient range queries. The project distinguishes itself through a hierarchical data organization model, allowing buckets to be nested within other buckets to create a tree-like structure. It employs a single-writer, multi-reader locking mechanism and copy-on-write transactions to ensure serializable isolation and data integrity. The system includes comprehensive data management capa