SELECT * FROM (
  SELECT count(1) cnt,t.sql_id,sql_text, event
  FROM   dba_hist_active_sess_history t
         left join gv$sql s on s.SQL_ID = t.sql_id
  where  t.sample_time between to_date('27.03.2019 18:04:57','dd.mm.yyyy hh24:mi:ss') and to_date('27.03.2019 19:04:17','dd.mm.yyyy hh24:mi:ss')
  group by t.sql_id,sql_text,event
  order by 1 desc)
where rownum<=10