script for historical blocking and locking session in the database

Below are the useful script for DBA to get historical blocking and locking session in the database

SELECT  distinct a.sql_id ,a.inst_id, a.blocking_session,a.blocking_session_serial#,a.user_id,s.sql_text,a.module

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

and a.sample_time > sysdate-11;

SELECT  distinct a.sql_id, a.blocking_session,a.blocking_session_serial#,

a.user_id,s.sql_text,a.module

FROM  V$ACTIVE_SESSION_HISTORY a, v$sql s

where a.sql_id=s.sql_id

and blocking_session is not null

and a.user_id <> 0

and a.sample_time between to_date('08/01/2018 17:00', 'dd/mm/yyyy hh24:mi')

and to_date('08/01/2018 17:30', 'dd/mm/yyyy hh24:mi');

I hope this helps. 

Thank you!!