-- Duration between 2 timestamps
SELECT (extract(DAY FROM TIME2 - TIME1) * 24 * 60 * 60)
+ (extract(HOUR FROM TIME2 - TIME1) * 60 * 60)
+ (extract(MINUTE FROM TIME2 - TIME1) * 60)
+ extract(SECOND FROM TIME2 - TIME1)
FROM DUAL;
SELECT JOB_NAME,
avg(extract(DAY FROM run_duration) * 24 * 60 * 60
+ extract(HOUR FROM run_duration) * 60 * 60
+ extract(MINUTE FROM run_duration) * 60
+ extract(SECOND FROM run_duration))
FROM DBA_SCHEDULER_JOB_RUN_DETAILS
WHERE JOB_NAME = 'my_job_name'
GROUP BY JOB_NAME;