The PostgreSQL Workload Analyzer is performance tool for PostgreSQL 9.4 and
later versions, allowing to collect, aggregate and purge statistics on a
PostgreSQL instance from various sources. It is implemented as a background
worker.

Install databases/powa-archivist on your database servers, and this port
on any achine with psql access to the databases.

WWW: http://powa.readthedocs.org/