我有一张大表，大约有2000万条记录。表及其索引的结构是：
CREATE TABLE `fact_ra` (
`replacement_record_id` varchar(45) NOT NULL,
`product_tree_1` varchar(45) NOT NULL,
`product_tree_2` varchar(45) NOT NULL,
`product_tree_3` varchar(45) NOT NULL,
`product_tree_4` varchar(45) NOT NULL,
`claim_owner` varchar(255) DEFAULT NULL,
`product_date` date DEFAULT NULL,
`month` date DEFAULT NULL,
`m1` decimal(10,0) DEFAULT NULL,
`m2` decimal(10,0) DEFAULT NULL,
`m3` decimal(10,0) DEFAULT NULL,
`m4` decimal(10,0) DEFAULT NULL,
`m5` decimal(10,0) DEFAULT NULL,
`m6` decimal(10,0) DEFAULT NULL,
`m7` decimal(10,0) DEFAULT NULL,
`m8` decimal(10,0) DEFAULT NULL,
`m9` decimal(10,0) DEFAULT NULL,
`m10` decimal(10,0) DEFAULT NULL,
`m11` decimal(10,0) DEFAULT NULL,
`m12` decimal(10,0) DEFAULT NULL,
`m13` decimal(10,0) DEFAULT NULL,
`m14` decimal(10,0) DEFAULT NULL,
`m15` decimal(10,0) DEFAULT NULL,
`m16` decimal(10,0) DEFAULT NULL,
`m17` decimal(10,0) DEFAULT NULL,
`m18` decimal(10,0) DEFAULT NULL,
`m19` decimal(10,0) DEFAULT NULL,
`m20` decimal(10,0) DEFAULT NULL,
`m21` decimal(10,0) DEFAULT NULL,
`m22` decimal(10,0) DEFAULT NULL,
`m23` decimal(10,0) DEFAULT NULL,
`m24` decimal(10,0) DEFAULT NULL,
`m25` decimal(10,0) DEFAULT NULL,
`m26` decimal(10,0) DEFAULT NULL,
`m27` decimal(10,0) DEFAULT NULL,
`m28` decimal(10,0) DEFAULT NULL,
`m29` decimal(10,0) DEFAULT NULL,
`m30` decimal(10,0) DEFAULT NULL,
`m31` decimal(10,0) DEFAULT NULL,
`m32` decimal(10,0) DEFAULT NULL,
`m33` decimal(10,0) DEFAULT NULL,
`m34` decimal(10,0) DEFAULT NULL,
`m35` decimal(10,0) DEFAULT NULL,
`m36` decimal(10,0) DEFAULT NULL,
`m37` decimal(10,0) DEFAULT NULL,
`m38` decimal(10,0) DEFAULT NULL,
`m39` decimal(10,0) DEFAULT NULL,
`m40` decimal(10,0) DEFAULT NULL,
`m41` decimal(10,0) DEFAULT NULL,
`m42` decimal(10,0) DEFAULT NULL,
`m43` decimal(10,0) DEFAULT NULL,
`m44` decimal(10,0) DEFAULT NULL,
`m45` decimal(10,0) DEFAULT NULL,
`m46` decimal(10,0) DEFAULT NULL,
`m47` decimal(10,0) DEFAULT NULL,
`m48` decimal(10,0) DEFAULT NULL,
`m49` decimal(10,0) DEFAULT NULL,
`m50` decimal(10,0) DEFAULT NULL,
`m51` decimal(10,0) DEFAULT NULL,
`m52` decimal(10,0) DEFAULT NULL,
`m53` decimal(10,0) DEFAULT NULL,
`m54` decimal(10,0) DEFAULT NULL,
`m55` decimal(10,0) DEFAULT NULL,
`m56` decimal(10,0) DEFAULT NULL,
`m57` decimal(10,0) DEFAULT NULL,
`m58` decimal(10,0) DEFAULT NULL,
`m59` decimal(10,0) DEFAULT NULL,
`m60` decimal(10,0) DEFAULT NULL,
PRIMARY KEY (`replacement_record_id`),
KEY `idx_product_tree_1` (`product_tree_1`),
KEY `idx_product_tree_2` (`product_tree_2`),
KEY `idx_product_tree_3` (`product_tree_3`),
KEY `idx_product_tree_4` (`product_tree_4`),
KEY `idx_month` (`month`),
FULLTEXT KEY `fidx_claim_owner` (`claim_owner`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
我正在运行以下查询：
select case when month(product_date) >= 4 then concat(year(product_date), \'-\',
year(product_date)+1) else concat(year(product_date)-1,\'-\', year(product_date)) end as
financial_year, sum(t1.m1) as m1, sum(t1.m2) as m2, sum(t1.m3) as m3, sum(t1.m4) as m4,
sum(t1.m5) as m5, sum(t1.m6) as m6, sum(t1.m7) as m7, sum(t1.m8) as m8, sum(t1.m9) as m9,
sum(t1.m10) as m10, sum(t1.m11) as m11, sum(t1.m12) as m12, sum(t1.m13) as m13,
sum(t1.m14) as m14, sum(t1.m15) as m15, sum(t1.m16) as m16, sum(t1.m17) as m17,
sum(t1.m18) as m18, sum(t1.m19) as m19, sum(t1.m20) as m20, sum(t1.m21) as m21,
sum(t1.m22) as m22, sum(t1.m23) as m23, sum(t1.m24) as m24, sum(t1.m25) as m25,
sum(t1.m26) as m26, sum(t1.m27) as m27, sum(t1.m28) as m28, sum(t1.m29) as m29,
sum(t1.m30) as m30, sum(t1.m31) as m31, sum(t1.m32) as m32, sum(t1.m33) as m33,
sum(t1.m34) as m34, sum(t1.m35) as m35, sum(t1.m36) as m36, sum(t1.m37) as m37,
sum(t1.m38) as m38, sum(t1.m39) as m39, sum(t1.m40) as m40, sum(t1.m41) as m41,
sum(t1.m42) as m42, sum(t1.m43) as m43, sum(t1.m44) as m44, sum(t1.m45) as m45,
sum(t1.m46) as m46, sum(t1.m47) as m47, sum(t1.m48) as m48, sum(t1.m49) as m49,
sum(t1.m50) as m50, sum(t1.m51) as m51, sum(t1.m52) as m52, sum(t1.m53) as m53,
sum(t1.m54) as m54, sum(t1.m55) as m55, sum(t1.m56) as m56, sum(t1.m57) as m57,
sum(t1.m58) as m58, sum(t1.m59) as m59, sum(t1.m60) as m60 from fact_ra t1
where month >= '2008-4-1' and month <= '2013-11-1' and claim_owner like '%test%'
and product_tree_1 = 'abc' group by financial_year
但是查询需要花费很多时间，这是我得到的解释计划：
+----+-------------+-------+------+------------------------------+--------------------+---------+-------+------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+------------------------------+--------------------+---------+-------+------+----------------------------------------------+
| 1 | SIMPLE | t1 | ref | idx_product_tree_1,idx_month | idx_product_tree_1 | 137 | const | 1 | Using where; Using temporary; Using filesort |
+----+-------------+-------+------+------------------------------+--------------------+---------+-------+------+----------------------------------------------+
如何提高此查询的效果，谢谢
答案 0 :(得分：-1)
以下是一些可能会有所帮助的事情。
正如xavierhao在上面的评论中所提到的，你应该尝试使用product_date上的索引。
ALTER TABLE `fact_ra` ADD INDEX `idx_product_date` (product_date);
如果这不能提高性能，那么你可以试试这个：
ALTER TABLE `fact_ra` ADD financial_year char(4) AFTER product_date;
然后根据您上面的逻辑运行更新以设置财务年度，因此，如果是2013年1月，您将其设置为2012年，因为它低于去年。
在financial_year上添加一个索引并试一试。
这样，您的分组不必处理计算值，可以直接使用索引。
如果这些没有帮助，请发布更多细节，我会看看我是否可以进一步提供帮助。