Information
The log_line_prefix setting specifies a printf-style string that is prefixed to each log line. If blank, no prefix is used. You should configure this as recommended by the pgBadger development team unless directed otherwise by your organization's logging policy.
    % characters begin 'escape sequences' that are replaced with status information as outlined below. Unrecognized escapes are ignored. Other characters are copied straight to the log line. Some escapes are only recognized by session processes and will be treated as empty by background processes such as the main server process. Status information may be aligned either left or right by specifying a numeric literal after the % and before the option. A negative value will cause the status information to be padded on the right with spaces to give it a minimum width, whereas a positive value will pad on the left. Padding can be useful to aid human readability in log files.
      Any of the following escape sequences can be used:
      Escape  Effect                                            Session only
    %a      Application name                                  yes
    %u      User name                                         yes
    %d      Database name                                     yes
    %r      Remote host name or IP address, and remote port   yes
    %h      Remote host name or IP address                    yes
    %p      Process ID                                        no
    %t      Time stamp without milliseconds                   no
    %m      Time stamp with milliseconds                      no
    %i      Command tag: type of session's current command    yes
    %e      SQLSTATE error code                               no
    %c      Session ID: see below                             no
    %l      Number of the log line for each session
      or process, starting at 1                         no
    %s      Process start time stamp                          no
    %v      Virtual transaction ID (backendID/localXID)       no
    %x      Transaction ID (0 if none is assigned)            no
    %q      Produces no output, but tells non-session
      processes to stop at this point in the string;
      ignored by session processes                      no
    %%      Literal %
      Rationale:
      Properly setting log_line_prefix allows for adding additional information to each log entry (such as the user, or the database). Said information may then be of use in auditing or security reviews.
Solution
Execute the following SQL statement(s) to remediate this setting:
      postgres=# alter system set log_line_prefix = '%m [%p]: [%l-1] db=%d,user=%u,app=%a,client=%h ';
      ALTER SYSTEM
      postgres=# select pg_reload_conf();
      pg_reload_conf
      ----------------
      t
    (1 row)
      Default Value:
    %m [%p]