Postgres

PostgreSQL, often just called Postgres, is a mature open-source object-relational database management system tracing its lineage back to the POSTGRES project at UC Berkeley in the 1980s and developed since the mid-1990s by a global community known as the PostgreSQL Global Development Group. It combines full SQL standard compliance with extensibility features rarely found together in one engine, including custom data types, procedural languages, foreign data wrappers, and a rich extension ecosystem such as PostGIS for spatial data and pgvector for AI embeddings. Multiversion concurrency control (MVCC) lets readers and writers operate without blocking each other while preserving ACID guarantees across four isolation levels. Released under the permissive PostgreSQL License, similar to BSD/MIT, it runs on every major operating system and underpins production workloads at companies like Uber, Reddit, and Instagram.