PostgreSQL

PostgreSQL is a powerful open-source relational database system with over thirty years of active development, originating from the POSTGRES project at the University of California, Berkeley in 1986 under professor Michael Stonebraker, and released under its current name in 1996. The SQL implementation supports window functions, recursive common table expressions, full outer joins, lateral subqueries, grouping sets, array operations, and row-level security policies. The indexing options include B-tree, Hash, GiST, SP-GiST, GIN for full-text search and JSONB, and BRIN for large tables. The JSONB data type enables efficient document-style queries with GIN-indexed binary JSON storage. The MVCC concurrency model provides snapshot isolation without read locks. The extensibility system supports custom data types, operators, functions, and procedural languages including PL/pgSQL, PL/Python, and PL/V8. The streaming replication and logical replication features enable high availability and data distribution. Major companies using PostgreSQL include Apple, Spotify, Instagram, Reddit, and Sony Online Entertainment. The current version 16 improved parallel query performance and added SQL standard JSON support. Designed for database administrators, backend developers, and data engineers.