Type: integer
Default: 0
Min: 0
Max: 262143
Context: postmaster
Restart: true
Since: 16

Determines the number of connection slots that are reserved for connections by roles with privileges of the pg_use_reserved_connections role. Whenever the number of free connection slots is greater than guc-superuser-reserved-connections but less than or equal to the sum of superuser_reserved_connections and reserved_connections, new connections will be accepted only for superusers and roles with privileges of pg_use_reserved_connections. If superuser_reserved_connections or fewer connection slots are available, new connections will be accepted only for superusers.

The default value is zero connections. The value must be less than max_connections minus superuser_reserved_connections. This parameter can only be set at server start.