Major enhancements in PostgreSQL 9.3 include:
- 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
URL: http://www.postgresql.org/docs/9.3/static/release-9-3.html