EXPLAIN plans can be output in XML, JSON, or YAML formats, to make it easier to analyze them with external tools (or to write such tools yourself). EXPLAIN (BUFFERS) allows monitoring of the actual I/O done by a particular query, instead of just showing its costs. EXPLAIN output shows more information about how the increasingly useful hash nodes in query plans.
Window functions have some new options, such as PRECEDING, FOLLOWING, and starting with CURRENT ROWS, all of which allow writing some new types of windowed queries. Outer joins that reference tables not actually used to satisfy the query can now be removed from the query plan to improve their performance. Queries with that issue are commonly created by object-relational ...
