packages. postgresql95-upgrade is gone, the pg_upgrade tool is shipped
with postgresql95-client now.
Major enhancements in PostgreSQL 9.5 include:
Allow INSERTs that would generate constraint conflicts to be turned into
UPDATEs or ignored
Add GROUP BY analysis features GROUPING SETS, CUBE and ROLLUP
Add row-level security control
Create mechanisms for tracking the progress of replication, including
methods for identifying the origin of individual changes during logical
replication
Add Block Range Indexes (BRIN)
Substantial performance improvements for sorting
Substantial performance improvements for multi-CPU machines