Inactive Users Report
Identify PostgreSQL users that have not shown database activity during a selected period. This helps administrators review dormant accounts and determine whether unnecessary access should be disabled or removed, reducing the risk associated with stale user accounts.
We parse PostgreSQL logs and aggregate the results over time to provide accurate insights into database activity. While pg_stat_statements can provide estimates, log parsing offers greater accuracy and more detailed information.
Note: The Log Parser module also provides several additional security and monitoring features, including the Common Users Report, Unused HBA Lines Report, and Client IP Report.

Common Users Report
Please watch demo video https://www.youtube.com/watch?v=Sws1x-UOb70
Below is sample report

There are many common usernames that people use (sample list below). It is not advisable to use common usernames from security point of view
"postgres",
"admin",
"administrator",
"pga",
"superuser",
"dba",
"web",
"website",
"django",
"flask",
"drupal",
"wordpress",
"postgresadmin",
"root",
"dbadmin",
"dbuser",
"sysadmin"