  id int(10) unsigned not_null auto_increment comment(Primary key - unique identifier for each page)
  user_id varchar(255) not_null comment(id of administrator - unique administrator id)
  started_at int(10) unsigned not_null comment(Start date)
  process_id int(10) unsigned default null comment(process id)

  --
  primary id
  idx_user_id user_id
  idx_started_at started_at
  idx_user_started user_id started_at

  ##
  engine innodb
  character_set utf8mb4
  collate utf8mb4_unicode_ci