Complete output off this function for me is:
array(13) {
  ["client"]=>
  string(5) "9.6.9"
  ["protocol"]=>
  int(3)
  ["server"]=>
  string(4) "12.1"
  ["server_encoding"]=>
  string(4) "UTF8"
  ["client_encoding"]=>
  string(4) "UTF8"
  ["is_superuser"]=>
  string(2) "on"
  ["session_authorization"]=>
  string(8) "postgres"
  ["DateStyle"]=>
  string(8) "ISO, MDY"
  ["IntervalStyle"]=>
  string(8) "postgres"
  ["TimeZone"]=>
  string(10) "US/Arizona"
  ["integer_datetimes"]=>
  string(2) "on"
  ["standard_conforming_strings"]=>
  string(2) "on"
  ["application_name"]=>
  string(0) ""
}