YugabyteDB Distributed SQL Database

YugabyteDB is a free and open-source, high-performance, distributed SQL database for global, internet-scale applications. Created by Kannan Muthukkaruppan, Karthik Ranganathan, and Mikhail Bautin (former Facebook engineers who worked on Cassandra and HBase) in 2016, Yugabyte Inc. is headquartered in Sunnyvale, California, and has raised over $291 million in funding (including a $188M Series C in 2021 led by Sapphire Ventures). YugabyteDB combines PostgreSQL compatibility with horizontal scalability. Key features: PostgreSQL compatibility: YugabyteDB reuses the PostgreSQL query layer (the upper half of PostgreSQL including the SQL parser, planner, optimizer, and execution engine), providing wire-level compatibility with PostgreSQL. Applications can use standard PostgreSQL drivers (psycopg2, JDBC, libpq) and existing PostgreSQL skills. Distributed storage: the lower half uses a custom distributed storage layer inspired by Google Spanner. Data is automatically sharded and replicated across nodes using Raft consensus for strong consistency. Tablets (shard replicas) are distributed for fault tolerance. SQL features: full ACID transactions with serializable isolation, foreign keys, JOINs, triggers, stored procedures, and partitioning. Geographic distribution: multi-region and multi-cloud deployments with synchronous replication for low RPO (Recovery Point Objective). Async replication for read replicas in distant regions. Tablet splitting: automatic tablet splitting for load balancing as data grows. PostgreSQL extensions: support for PostGIS, pgcrypto, pg_stat_statements. Yugabyte Cloud: managed YugabyteDB service on AWS, GCP, and Azure. C++/PostgreSQL. Apache-2.0.