Today GreenplumDB 6.0 official version has been released.
GreenplumDB 6 contains a number of new features, significant performance optimization including the core Postgres upgrade from version 8.3 to 9.4, copy the table, concurrent update, and delete HEAP tables, use zStandard algorithms faster and more efficient data compression, disk quotas, JSONB data types, text and JSON support GIN index, column-level security, query optimization and improve the implementation of and so on.
Update list is very long, details see Greenplum changes from v5 to v6 of .