After many years of development, PostgreSQL has become feature-complete in many areas. This release shows a targeted approach to adding features (e.g., authentication, monitoring, space reuse), and adds capabilities defined in the later SQL standards. The major areas of enhancement are: * Windowing Functions
* Common Table Expressions and Recursive Queries
* Default and variadic parameters for functions
* Parallel Restore
* Column Permissions
* Per-database locale settings
* Improved hash indexes
* Improved join performance for EXISTS and NOT EXISTS queries
* Easier-to-use Warm Standby
* Automatic sizing of the Free Space Map
* Visibility Map (greatly reduces vacuum overhead for slowly-changing tables)
* Version-aware psql (backslash commands work against older servers)
* Support SSL certificates for user authentication
* Per-function runtime statistics
* Easy editing of functions in psql
* New contrib modules: pg_stat_statements, auto_explain, citext, btree_gin