Some (long) time ago, someone on irc suggested that I add option to keep track of optimizations of queries. Sorry, I forgot your name, and the mails disappeared in some crash. Anyway - right now, when you are on some plan page, ...

On 21st of March, Robert Haas committed patch: Support parallel aggregation. Parallel workers can now partially aggregate the data and pass the transition values back to the leader, which can combine the partial results to produce the final answer. David Rowley, based on earlier work ...

On 11th of February, Tom Lane committed patch: Remove GROUP BY columns that are functionally dependent on other columns. If a GROUP BY clause includes all columns of a non-deferred primary key, as well as other columns of the same relation, those other ...

On 20th of March, Andres Freund committed patch: Use 128-bit math to accelerate some aggregation functions. On platforms where we support 128bit integers, use them to implement faster transition functions for sum(int8), avg(int8), var_*(int2/int4),stdev_*(int2/int4). Where not supported continue to use numeric as a transition type. In ...