Monitoring Postgresql

https://www.postgresql.org/docs/current/static/monitoring-stats.html
https://blog.pandorafms.org/how-to-monitor-postgress/
https://wiki.postgresql.org/wiki/Disk_Usage
https://www.enterprisedb.com/monitor-cpu-and-memory-percentage-used-each-process-postgresqlppas-91
https://aaronparecki.com/2015/02/19/8/monitoring-cpu-memory-usage-from-postgres
https://wiki.postgresql.org/wiki/Performance_Analysis_Tools

https://russ.garrett.co.uk/2015/10/02/postgres-monitoring-cheatsheet/
http://opm.io