Question: how to calculate the time difference in oracle sql?
Answer: select to_char(to_date('1970-01-01 00:00:00', 'yyyy-mm-dd hh24:mi:ss')+(end_date - start_date),'hh24:mi:ss') as run_time from some_table; It displays time in more human readable form, like: 00:01:34. If you need also days you may simply add DD to last formatting string.