awesome-db

Open source relational database implemented entirely in Java

Duckdb

In-process SQL OLAP Database Management System

HaloDB

Java fast, log structured key-value store

H2

H2 is an embeddable RDBMS written in Java

LevelDB

LevelDB is a fast key-value storage library written at Google

lmdbjava

Lightning Memory Database (LMDB) for Java

PalDB

Embeddable write-once key-value store written in Java

RocksDB

Library that provides an embeddable, persistent key-value store for fast storage

MapDB

Fast and easy to use embedded Java database engine

Xodus

JetBrains Xodus is a Java transactional schema-less embedded database

verneuil

VFS extension for SQLite that asynchronously replicates databases to S3-compatible blob stores

Litestream

Streaming replication for SQLite

whippet-db

Fast embedded key-value database engine for Java

SwayDB

Persistent and in-memory key-value storage engine for the JVM that scales on a single machine

immutable database based on zero trust, SQL and Key-Value, tamperproof, data change history