计算每次调用递归函数所花费的时间....在SQL

Question

我有如下数据

id | Function_name | event | time
1     function_a     start   12:01
2     function_a     start   12:02
3     function_a     start   12:03
4     function_a     end     12:04
5     function_a     start   12:05
6     function_a     end     12:06
7     function_a     end     12:07
8     function_a     end     12:08

在上面的数据中，function_a被递归调用了4次，并记录了函数的开始和结束。我需要捕获每个函数调用所花费的时间。上述 table 的输出应如下所示。

Function_call_id | time_taken_for_function_call(seconds)
1                   7
2                   5
3                   1
4                   1

Answer 1

您可以枚举调用然后聚合。这枚举了开始和停止

select t.*,
       (next_time - time) as diff
from (select t.*, lead(time) over (partition by grp order by id) as next_time
      from (select t.*,
                   (sum(case when event = 'start' then 1 else -1 end) over (order by id) +
                    (case when event = 'end' then 1 else 0 end)
                   ) as grp
            from t
           ) t
     ) t
where event = 'start';

计算每次调用递归函数所花费的时间....在SQL

Calculate the time taken by a recursive function each time it is called.... in SQL

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