PostgreSQL (/ˈpoʊstɡrɛs ˌkjuː ˈɛl/, POHST-gres kyoo el), also known as Postgres, is a free and open-source relational database management system (RDBMS) emphasizing extensibility and SQL compliance. … PostgreSQL. The World’s Most Advanced Open Source Relational DatabaseDeveloper(s)PostgreSQL Global Development GroupTypeRDBMSPostgreSQL – Wikipedia en.wikipedia.org › wiki › PostgreSQL