This PostgreSQL release focuses on one of the major performance features which is called parallelism of existing features. This release adds parallelism in sequential scans, joins, and aggregates. This also added new postgres_fdw remote joins, sorts, UPDATEs, and DELETEs. Here is the list of some performance features but you can always get the complete listing from here:
https://www.postgresql.org/docs/9.6/static/release-9-6.html
Let's look at the features:
- Allow old MVCC snapshots to be invalidated after a configurable timeout
- Index-only scan can be used even if restriction clause column not indexed
- Perform checkpoint writes in sorted order, instead of random order
- Improve the performance of aggregate-function by dividing the calculation across multiple aggregates
- Allow tuple hint bits to be set sooner than before
- Improve performance of short-lived prepared transactions, resource owners with many tracked objects, and memory context destruction
- Improve the performance of timestamp, date and time data type's output function
- Increase the number of clog buffers for better scalability
- Avoid reducing the SO_SNDBUF setting below its default on recent Windows versions