Using Oracle
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\nUsing Oracle and Case Statement\n\n# Complexity\n- Time complexity:\n Add
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\nUsing Oracle and Case Statement\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 \n    round(sum(temp)/count(distinct player_id), 2) as fraction\nfrom \n(select\n    player_id,\n    case when event_date - min (event_date) over (partition by player_id) = 1 then 1 else 0 end as temp\n  from \n    Activity\n) A\n```
['Oracle']