Find blocking sessions from ash - oracle database script

--- Query will list the blocking session details between SYSDATE - 1 AND SYSDATE-23/24 ( PAST)  set pagesize 50 set linesize 120 col sql_id format a15 col inst_id format '9' col sql_text format a50 col module format a10 col blocker_ses format '999999' col blocker_ser format '999999' SELECT distinct a.sql_id , a.inst_id, a.blocking_session blocker_ses, a.blocking_session_serial# blocker_ser, a.user_id, s.sql_text, a.module,a.sample_time FROM GV$ACTIVE_SESSION_HISTORY a, gv$sql s where a.sql_id=s.sql_id and blocking_session is not null and a.user_id <> 0 -- exclude SYS user and a.sample_time BETWEEN SYSDATE - 1 AND SYSDATE-23/24 /