Every major version includes a wide range of improvements in various areas. Let’s see the main performance-related improvements in 9.5, either improving existing features (sorting, hash joins, bitmap index scans) or entirely new features (BRIN indexes, parallel scans).
We’ll also look at the main improvements to be expected in 9.6 (parallel aggregate, joins, improvements to indexes, etc.).
Here you will find the slides from the talk Performance Improvements in PostgreSQL 9.5 & 9.6.