改進 SQL 查詢運行時

Question

SQL 的新手。我正在嘗試獲取一些每周的趨勢來比較各種指標點。 這是我到目前為止所擁有的。 運行時很糟糕，因為它遍歷整個表 4 次，而且這只是過去 4 周的情況。 有沒有什么方法可以改進這個過程並獲得過去幾周（不僅僅是過去 4 周）的指標？

編輯：這是 MySQL。

樣本數據：

時間戳	指標命中	公制合計	指標值
2022-09-20 06:50:01.332000	4個	4個	1個
2022-08-31 08:49:59.086000	2個	3個	0.6666
2022-08-09 04:50:12.430000	1個	2個	0.5

SELECT
    sum(metric_hits) as metric_hits_sum,
    sum(metric_total) as metrics_total_sum,
    avg(metric_value) as metric_value_avg
from metric_events
where timestamp >= DATEADD(DAY, -7-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date) and timestamp < DATEADD(DAY, -DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date)
UNION
SELECT
    sum(metric_hits) as metric_hits_sum,
    sum(metric_total) as metrics_total_sum,
    avg(metric_value) as metric_value_avg
from metric_events
where timestamp >= DATEADD(DAY, -14-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date) and timestamp < DATEADD(DAY, -7-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date)
UNION
SELECT
    sum(metric_hits) as metric_hits_sum,
    sum(metric_total) as metrics_total_sum,
    avg(metric_value) as metric_value_avg
from metric_events
where timestamp >= DATEADD(DAY, -21-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date) and timestamp < DATEADD(DAY, -14-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date)
UNION
SELECT
    sum(metric_hits) as metric_hits_sum,
    sum(metric_total) as metrics_total_sum,
    avg(metric_value) as metric_value_avg
from metric_events
where timestamp >= DATEADD(DAY, -28-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date) and timestamp < DATEADD(DAY, -21-DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date)

Answer 1

這應該讓你更接近。 我會讓你添加更多功能（比如一周的開始和結束日期）

select floor((daysold - DATEPART(WEEKDAY, GETDATE()::date)) / 7) as weeksold
, sum(metric_hits) as metric_hits_sum
, sum(metric_total) as metrics_total_sum
, avg(metric_value) as metric_value_avg
from (
  SELECT datediff(day, [timestamp], GETDATE()::date) as daysold
  , metric_hits
  , metric_total
  , metric_value
  from metric_events
  where [timestamp] < DATEADD(DAY, -DATEPART(WEEKDAY, GETDATE()::date), GETDATE()::date)
) q
group by floor((daysold - DATEPART(WEEKDAY, GETDATE()::date)) / 7)
order by 1