Example of fetching last one hour or Minutes time from SYSDATE
First set the NLD_DATE_FORMAT for session level
ALTER SESSION SET NLS_DATE_FORMAT='DD-MON-YY HH24:MI:SS';
Fetch last one hours report by using sysdate
select sysdate "Current Time", sysdate-1/24 "Last One hour" from dual;
Current Time Last One hour ------------------ ------------------ 23-FEB-21 09:29:12 23-FEB-21 08:29:12
Fetch last 4 hours report by using sysdate
select sysdate "Current Time", sysdate-4/24 "Last Four hour" from dual;
Current Time Last Four hour ------------------ ------------------ 23-FEB-21 09:31:13 23-FEB-21 05:31:13
Fetch last 24 hours or 1 day from current datetime
SQL> select sysdate "Current Time", sysdate-1 "Last One Day" from dual;
Current Time Last One Day ------------------ ------------------ 23-FEB-21 09:30:15 22-FEB-21 09:30:15
Fetch one or 5 minute last data example from current datetime
select sysdate "Current Time", sysdate-1/(24*60) "Last one Minutes" from dual;
Current Time Last one Minutes ------------------ ------------------ 23-FEB-21 14:52:32 23-FEB-21 14:51:32
SQL> select sysdate "Current Time", sysdate-5/(24*60) "Last Five Minutes" from dual;
Current Time Last Five Minutes ------------------ ------------------ 23-FEB-21 14:51:58 23-FEB-21 14:46:58
