Other Features of PostgreSQL

* Table inheritance, that a new table will have all the fields of an existing table.

* Table columns as arrays that can store more than one value.

* Add fields to tables at run-time.

* User-defined aggregate functions - like count or sum.

* Rules - SQL commands to be executed instead or along with other SQL commands.

* Triggers - SQL commands to be executed when a table is changed by either INSERT, UPDATE or DELETE.

* System tables that can be queried to retrieve database and tables information. (Fields in a table, Tables in a database, etc.)

* API for managing large objects.