oracle solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nselect a.machine_id  , round(avg(b.timestamp - a.timestamp),3) as processing_time\n from activity a join activity b \non a.machine_id = b.machine_id\nand a.process_id = b.process_id\nwhere a.timestamp < b.timestamp \ngroup by a.machine_id;\n```
['Oracle']