PostgreSQL

There are several major new features in this release, including synchronous replication and other replication features, per-column collations, unlogged tables, extensions, K-Nearest-Neighbor indexing, Serializable Snapshot Isolation, Writeable Common Table Expressions, SE-Postgres (Military-grade security), the PostgreSQL Extension Network, and SQL/MED (Management of External Data), with foreign data wrappers for Oracle, MySQL, CouchDB, Redis, CSV, Twitter, and more. There have also been improvements in performance and database administration, and several SQL and PL/PgSQL features.