PostgreSQL

# Major enhancements:
* Add materialized views
* Make simple views auto-updatable
* Add many features for the JSON data type, including operators and functions to extract elements from JSON values
* Implement SQL-standard LATERAL option for FROM-clause subqueries and function calls
* Allow foreign data wrappers to support writes (inserts/updates/deletes) on foreign tables
* Add a Postgres foreign data wrapper to allow access to other Postgres servers
* Add support for event triggers
* Add optional ability to checksum data pages and report corruption
* Prevent non-key-field row updates from blocking foreign key checks
* Greatly reduce System V shared memory requirements