今天客户反馈有一个报表运行超时。
于是登录到系统上,查到运行缓慢报表的对应sql,代码如下:
SELECT f_temp_biz_date AS f_temp_biz_date , o_id2 AS o_id2 , o_id3 AS o_id3 , o_id4 AS o_id4 , storeChannel_id2 AS storeChannel_id2 , storeChannel_id3 AS storeChannel_id3 , g_A_item_id AS g_A_item_id , A_item_id AS A_item_id , MAX(CASE WHEN f_unit = '当月销量(L)' AND p_brand_id = '11083' THEN M001 END) , MAX(CASE WHEN f_unit = '当月销量(L)' AND p_brand_id = '11207' THEN M001 END) , ...此处省略100行 MAX(CASE WHEN f_unit = '当月销量(Box)' AND p_brand_id = '11055' THEN M001 END) , MAX(CASE WHEN f_unit = '当月销量(Box)' AND p_brand_id = '11056' THEN M001 END) FROM ( SELECT f.temp_biz_date AS f_temp_biz_date , o.id2 AS o_id2 , o.id3 AS o_id3 , o.id4 AS o_id4 , storeChannel.id2 AS storeChannel_id2 , storeChannel.id3 AS storeChannel_id3 , GROUPING(A.item_id) AS g_A_item_id , A.item_id AS A_item_id , GROUPING(f.unit) AS g_f_unit , f.unit AS f_unit , GROUPING(p.brand_id) AS g_p_brand_id , p.brand_id AS p_brand_id , COUNT(CASE WHEN flag = 'store' THEN f.store_id END) AS M000 , SUM(CASE WHEN flag = 'HL_BOX' THEN HL_BOX ELSE 0 END) AS M001 FROM ( SELECT r.org_id , r.store_id , R.LEVEL_ID , r.channel_id , r.biz_date + '-01' AS biz_date , r.biz_date AS temp_biz_date , ISNULL(r.prod_id, t.prod_id) AS PROD_ID , HL_BOX , UNIT , flag FROM TB_S_001 r CROSS APPLY ( SELECT TOP 1 prod_id FROM TB_PRODUCT WITH ( NOLOCK ) WHERE state = 1 ) t WHERE r.biz_date IN ( '2016-08' ) ) f INNER JOIN STD_TIME t ON f.biz_date = t.the_date INNER JOIN STD_ORG o ON f.org_id = o.org_id INNER JOIN STD_STORE s ON f.store_id = s.store_id LEFT JOIN STD_PRODUCT p ON f.prod_id = p.prod_id INNER JOIN STD_ITEM storeChannel ON f.channel_id = storeChannel.item_id INNER JOIN STD_ITEM A ON f.level_id = A.item_id WHERE ( o.id2 = '516' ) AND ( o.id2 = '516' ) AND ( f.biz_date BETWEEN '2016-08-01' AND '2016-08-31' ) AND ( s.id2 = '516' ) GROUP BY f.temp_biz_date , o.id2 , o.id3 , o.id4 , storeChannel.id2 , storeChannel.id3 , A.item_id , f.unit , p.brand_id WITH CUBE HAVING NOT ( GROUPING(f.temp_biz_date) = 1 OR GROUPING(f.temp_biz_date) = 0 AND GROUPING(o.id2) = 1 OR GROUPING(o.id2) = 0 AND GROUPING(o.id3) = 1 OR GROUPING(o.id3) = 0 AND GROUPING(o.id4) = 1 OR GROUPING(o.id4) = 0 AND GROUPING(storeChannel.id2) = 1 OR GROUPING(storeChannel.id2) = 0 AND GROUPING(storeChannel.id3) = 1 OR GROUPING(A.item_id) = 0 AND GROUPING(storeChannel.id3) = 1 OR GROUPING(storeChannel.id3) = 0 AND GROUPING(storeChannel.id2) = 1 OR GROUPING(storeChannel.id2) = 0 AND GROUPING(o.id4) = 1 OR GROUPING(o.id4) = 0 AND GROUPING(o.id3) = 1 OR GROUPING(o.id3) = 0 AND GROUPING(o.id2) = 1 OR GROUPING(o.id2) = 0 AND GROUPING(f.temp_biz_date) = 1 ) ) cr GROUP BY f_temp_biz_date , o_id2 , o_id3 , o_id4 , storeChannel_id2 , storeChannel_id3 , g_A_item_id , A_item_id ORDER BY f_temp_biz_date , o_id2 , o_id3 , o_id4 , storeChannel_id2 , storeChannel_id3 , g_A_item_id
由于这个语句的外层是由工具生成的,修改不了,所以只能修改这个语句中最内层的的这个sql,能做的优化非常有限,sql语句上没有什么可以调整的。
SELECT r.org_id , r.store_id , R.LEVEL_ID , r.channel_id , r.biz_date + '-01' AS biz_date , r.biz_date AS temp_biz_date , ISNULL(r.prod_id, t.prod_id) AS PROD_ID , HL_BOX , UNIT , flag FROM TB_RPT_001 r CROSS APPLY ( SELECT TOP 1 prod_id FROM TB_PRODUCT WITH ( NOLOCK ) WHERE state = 1 ) t WHERE r.biz_date IN ( '2016-08' )
运行时间:最开始的速度是170s。
表信息:表中有大概800w条数据,这个查询的8月份,大概有80w的数据。
结果集:返回数据量在4w行左右。
优化方法:创建了索引,但是速度反而更慢了,运行了300s没有出结果。
因为这个表会经常删除,在插入,所以把整个表重建了,但是结果还是300s没有出结果。
经过分析发现这个语句之所以这么慢,主要的原因在于语句中的 with cube 造成的,执行计划非常复杂,一眼望不到头。
实际上在sql server 2008之后可以采用新的cube语句,只对需要的列进行cube计算,但关键是这个外层代码改不了,是工具生成的,太坑了。。。
下面的图就是这个sql的执行计划,由于这个执行计划太复杂,太大了,所以这个截图只是原始执行计划的5分之1 :
想想还可以试一下,就是修改sql server的服务器参数max degree of parallelism ,就是语句执行的并行度,服务器CPU配置是64个线程,所以把参数值调整为20,也就是可以有20个线程同时运行这个sql。
调整之后,sql运行速度降为10秒,太棒了。