我想在一个大型的表(超过800万行)上生成一个组查询。不过,我可以减少按日期分组所有数据的需要。我有一个观点,捕捉我需要的日期,这限制了查询BU它并不好多了。 最后,我需要加入到另一张桌子来选择一个字段。GROUP BY查询 - 为什么这么慢
我正在显示查询,主表上的创建和查询下面的解释。
主查询:
SELECT pgi_raw_data.wsp_channel,
'IOM' AS wsp,
pgi_raw_data.dated,
pgi_accounts.`master`,
pgi_raw_data.event_id,
pgi_raw_data.breed,
Sum(pgi_raw_data.handle),
Sum(pgi_raw_data.payout),
Sum(pgi_raw_data.rebate),
Sum(pgi_raw_data.profit)
FROM pgi_raw_data
INNER JOIN summary_max
ON pgi_raw_data.wsp_channel = summary_max.wsp_channel
AND pgi_raw_data.dated > summary_max.race_date
INNER JOIN pgi_accounts
ON pgi_raw_data.account = pgi_accounts.account
GROUP BY pgi_raw_data.event_id
ORDER BY NULL
创建表:
CREATE TABLE `pgi_raw_data` (
`event_id` char(25) NOT NULL DEFAULT '',
`wsp_channel` varchar(5) NOT NULL,
`dated` date NOT NULL,
`time` time DEFAULT NULL,
`program` varchar(5) NOT NULL,
`track` varchar(25) NOT NULL,
`raceno` tinyint(2) NOT NULL,
`detail` varchar(30) DEFAULT NULL,
`ticket` varchar(20) NOT NULL DEFAULT '',
`breed` varchar(12) NOT NULL,
`pool` varchar(10) NOT NULL,
`gross` decimal(11,2) NOT NULL,
`refunds` decimal(11,2) NOT NULL,
`handle` decimal(11,2) NOT NULL,
`payout` decimal(11,4) NOT NULL,
`rebate` decimal(11,4) NOT NULL,
`profit` decimal(11,4) NOT NULL,
`account` mediumint(10) NOT NULL,
PRIMARY KEY (`event_id`,`ticket`),
KEY `idx_account` (`account`),
KEY `idx_wspchannel` (`wsp_channel`,`dated`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=latin1
这是我summary_max观点:
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW
`summary_max` AS select `pgi_summary_tbl`.`wsp_channel` AS
`wsp_channel`,max(`pgi_summary_tbl`.`race_date`) AS `race_date`
from `pgi_summary_tbl` group by `pgi_summary_tbl`.`wsp
同时,也是评估查询:
1 PRIMARY <derived2> ALL 6 Using temporary
1 PRIMARY pgi_raw_data ref idx_account,idx_wspchannel idx_wspchannel
7 summary_max.wsp_channel 470690 Using where
1 PRIMARY pgi_accounts ref PRIMARY PRIMARY 3 gf3data_momutech.pgi_raw_data.account 29 Using index
2 DERIVED pgi_summary_tbl ALL 42282 Using temporary; Using filesort
索引的任何帮助都会有所帮助。
“pgi_summary_table”上的索引是什么? – Dancrumb