Major releases usually change the internal format of system tables
and data files. These changes are often complex, so we do not maintain
backward compatibility of all stored data. A dump/reload of the
database or use of the pg_upgrade module is required for major upgrades.
PostgreSQL is a powerful, open source object-relational database system.
It has a proven architecture that has earned it a strong reputation for
reliability, data integrity, and correctness.
It is fully ACID compliant, has full support for foreign keys, joins, views,
triggers, and stored procedures (in multiple languages).
It includes most SQL:2008 data types