The built in query stats is similar to Performance Schema in MySQL. The statistics are quite fine grained, and with a set of views on top (https://github.com/MarkLeith/mysql-sys) are very useful for observability.
Thanks, wasn't aware of that, quit mysql habits pre 5.6 :)
Technically, it was introduced in 5.5, but off by default :)
5.7 is going to be amazing for observability. Memory, transactions, stored procedures, replication, meta data locking and prepared statements are all instrumented in P_S.
Eg disabling connections per database using sql and having built-in query stats (http://www.postgresql.org/docs/9.4/static/pgstatstatements.h...) just made me smile.