我从 freeradius 更新了数据库，现在有一个 sql 语句需要更多的 tan 30 秒来执行，而之前只需要 0.5 秒来执行。
这是 OLD 定义表：
CREATE TABLE `radacct` (
`radacctid` bigint(21) NOT NULL AUTO_INCREMENT,
`acctsessionid` varchar(64) NOT NULL DEFAULT '',
`acctuniqueid` varchar(32) NOT NULL DEFAULT '',
`username` varchar(64) NOT NULL DEFAULT '',
`groupname` varchar(64) NOT NULL DEFAULT '',
`realm` varchar(64) DEFAULT '',
`nasipaddress` varchar(15) NOT NULL DEFAULT '',
`nasportid` varchar(15) DEFAULT NULL,
`nasporttype` varchar(32) DEFAULT NULL,
`acctstarttime` datetime DEFAULT NULL,
`acctstoptime` datetime DEFAULT NULL,
`acctsessiontime` int(12) DEFAULT NULL,
`acctauthentic` varchar(32) DEFAULT NULL,
`connectinfo_start` varchar(50) DEFAULT NULL,
`connectinfo_stop` varchar(50) DEFAULT NULL,
`acctinputoctets` bigint(20) DEFAULT NULL,
`acctoutputoctets` bigint(20) DEFAULT NULL,
`calledstationid` varchar(50) NOT NULL DEFAULT '',
`callingstationid` varchar(50) NOT NULL DEFAULT '',
`acctterminatecause` varchar(32) NOT NULL DEFAULT '',
`servicetype` varchar(32) DEFAULT NULL,
`framedprotocol` varchar(32) DEFAULT NULL,
`framedipaddress` varchar(15) NOT NULL DEFAULT '',
`acctstartdelay` int(12) DEFAULT NULL,
`acctstopdelay` int(12) DEFAULT NULL,
`xascendsessionsvrkey` varchar(10) DEFAULT NULL,
PRIMARY KEY (`radacctid`),
KEY `username` (`username`),
KEY `framedipaddress` (`framedipaddress`),
KEY `acctsessionid` (`acctsessionid`),
KEY `acctsessiontime` (`acctsessiontime`),
KEY `acctuniqueid` (`acctuniqueid`),
KEY `acctstarttime` (`acctstarttime`),
KEY `acctstoptime` (`acctstoptime`),
KEY `nasipaddress` (`nasipaddress`)
) ENGINE=InnoDB AUTO_INCREMENT=3514770 DEFAULT CHARSET=latin1;
CREATE TABLE `userinfo` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`username` varchar(128) DEFAULT NULL,
`firstname` varchar(200) DEFAULT NULL,
`lastname` varchar(200) DEFAULT NULL,
`email` varchar(200) DEFAULT NULL,
`department` varchar(200) DEFAULT NULL,
`company` varchar(200) DEFAULT NULL,
`workphone` varchar(200) DEFAULT NULL,
`homephone` varchar(200) DEFAULT NULL,
`mobilephone` varchar(200) DEFAULT NULL,
`address` varchar(200) DEFAULT NULL,
`city` varchar(200) DEFAULT NULL,
`state` varchar(200) DEFAULT NULL,
`country` varchar(100) DEFAULT NULL,
`zip` varchar(200) DEFAULT NULL,
`notes` varchar(200) DEFAULT NULL,
`changeuserinfo` varchar(128) DEFAULT NULL,
`portalloginpassword` varchar(128) DEFAULT '',
`enableportallogin` int(32) DEFAULT '0',
`creationdate` datetime DEFAULT '0000-00-00 00:00:00',
`creationby` varchar(128) DEFAULT NULL,
`updatedate` datetime DEFAULT '0000-00-00 00:00:00',
`updateby` varchar(128) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `username` (`username`),
KEY `company` (`company`)
) ENGINE=MyISAM AUTO_INCREMENT=188493 DEFAULT CHARSET=latin1;
这是新的定义表：
CREATE TABLE `radacct` (
`radacctid` bigint(21) NOT NULL AUTO_INCREMENT,
`acctsessionid` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctuniqueid` varchar(32) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`username` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`groupname` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`realm` varchar(64) COLLATE utf8_unicode_ci DEFAULT '',
`nasipaddress` varchar(15) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`nasportid` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL,
`nasporttype` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`acctstarttime` datetime DEFAULT NULL,
`acctstoptime` datetime DEFAULT NULL,
`acctsessiontime` int(12) DEFAULT NULL,
`acctauthentic` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`connectinfo_start` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
`connectinfo_stop` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
`acctinputoctets` bigint(20) DEFAULT NULL,
`acctoutputoctets` bigint(20) DEFAULT NULL,
`calledstationid` varchar(50) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`callingstationid` varchar(50) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctterminatecause` varchar(32) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`servicetype` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`framedprotocol` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`framedipaddress` varchar(15) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctstartdelay` int(12) DEFAULT NULL,
`acctstopdelay` int(12) DEFAULT NULL,
`xascendsessionsvrkey` varchar(10) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`radacctid`),
KEY `username` (`username`),
KEY `framedipaddress` (`framedipaddress`),
KEY `acctsessionid` (`acctsessionid`),
KEY `acctsessiontime` (`acctsessiontime`),
KEY `acctuniqueid` (`acctuniqueid`),
KEY `acctstarttime` (`acctstarttime`),
KEY `acctstoptime` (`acctstoptime`),
KEY `nasipaddress` (`nasipaddress`)
) ENGINE=MyISAM AUTO_INCREMENT=3519495 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
CREATE TABLE `userinfo` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`username` varchar(128) DEFAULT NULL,
`firstname` varchar(200) DEFAULT NULL,
`lastname` varchar(200) DEFAULT NULL,
`email` varchar(200) DEFAULT NULL,
`department` varchar(200) DEFAULT NULL,
`company` varchar(200) DEFAULT NULL,
`workphone` varchar(200) DEFAULT NULL,
`homephone` varchar(200) DEFAULT NULL,
`mobilephone` varchar(200) DEFAULT NULL,
`address` varchar(200) DEFAULT NULL,
`city` varchar(200) DEFAULT NULL,
`state` varchar(200) DEFAULT NULL,
`country` varchar(100) DEFAULT NULL,
`zip` varchar(200) DEFAULT NULL,
`notes` varchar(200) DEFAULT NULL,
`changeuserinfo` varchar(128) DEFAULT NULL,
`portalloginpassword` varchar(128) DEFAULT '',
`enableportallogin` int(32) DEFAULT '0',
`creationdate` datetime DEFAULT '0000-00-00 00:00:00',
`creationby` varchar(128) DEFAULT NULL,
`updatedate` datetime DEFAULT '0000-00-00 00:00:00',
`updateby` varchar(128) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `username` (`username`),
KEY `company` (`company`)
) ENGINE=MyISAM AUTO_INCREMENT=188894 DEFAULT CHARSET=latin1;
请注意，旧表同时具有 CHARSET=latin1，而根据定义，新表具有不同的字符集和整理：CHARSET=utf8 COLLATE=utf8_unicode_ci 和 CHARSET=latin1。这应该是区别。
现在这是我运行的句子：
select TIMESTAMPDIFF(SECOND,max(acctstarttime),now()) as segons,(department) as idClient,(userinfo.username)
from
(select radacct.username as id
from radacct,userinfo
where userinfo.company=98
and radacct.username = userinfo.username
group by userinfo.username
order by max(radacct.radacctid) desc limit 0,6) as tbl,radacct,userinfo
where radacct.username=tbl.id and radacct.username = userinfo.username
group by radacct.username
order by max(radacct.radacctid) desc;
这是 OLD TABLES - FAST 查询（0.4 秒）的 DESCRIBE：
id * select_type * table type possible_keys key key_len ref rows Extra *
1 PRIMARY <derived2> ALL {null} {null} {null} {null} 6 Using temporary; Using filesort
1 PRIMARY radacct ref username username 66 tbl.id 5
1 PRIMARY userinfo ref username username 131 radius.radacct.username 1 Using where
2 DERIVED radacct index username username 66 {null} 28768 Using index; Using temporary; Using filesort
2 DERIVED userinfo ref username,company username 131 radius.radacct.username 1 Using where
这是 NEW TABLES - SLOW 查询（30 秒）的 DESCRIBE：
id * select_type * table type possible_keys key key_len ref rows Extra *
1 PRIMARY <derived2> ALL {null} {null} {null} {null} 6 Using temporary; Using filesort
1 PRIMARY radacct ref username username 194 tbl.id 11
1 PRIMARY userinfo ALL {null} {null} {null} {null} 188911 Using where; Using join buffer
2 DERIVED userinfo ALL company {null} {null} {null} 188911 Using where; Using temporary; Using filesort
2 DERIVED radacct ref username username 194 func 11 Using where
谢谢。
编辑：
我更改用户信息的字符集：
alter table radius.userinfo convert to character set utf8 collate utf8_unicode_ci;
现在 NEW - Slow 查询在 3 秒内运行，但仍不如 OLD 数据库快。
此外，我在两个查询中都将 VARCHAR 长度更改为相同，并且仍然不像 OLD 数据库那样按索引进行。
ALTER TABLE radius.userinfo CHANGE username username VARCHAR(64);
我只是运行缓慢的子查询：
select radacct.username as id
from radacct,userinfo
where userinfo.company=98
and radacct.username = userinfo.username
group by userinfo.username
order by max(radacct.radacctid) desc limit 0,6
这是 DESCRIBE OLD - 快速：
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE radacct index username username 66 37545 Using index; Using temporary; Using filesort
1 SIMPLE userinfo ref username,company username 131 radius.radacct.username 1 Using where
这是 DESCRIBE NEW - 慢：
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE radacct ALL username 56879 Using temporary; Using filesort
1 SIMPLE userinfo ref company,username username 195 radius.radacct.username 1 Using where
为什么没有获得 radacct.username 索引？
编辑 2：使用新的 COLLATION-CHARSET 添加新定义。
CREATE TABLE `radacct` (
`radacctid` bigint(21) NOT NULL AUTO_INCREMENT,
`acctsessionid` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctuniqueid` varchar(32) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`username` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`groupname` varchar(64) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`realm` varchar(64) COLLATE utf8_unicode_ci DEFAULT '',
`nasipaddress` varchar(15) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`nasportid` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL,
`nasporttype` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`acctstarttime` datetime DEFAULT NULL,
`acctstoptime` datetime DEFAULT NULL,
`acctsessiontime` int(12) DEFAULT NULL,
`acctauthentic` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`connectinfo_start` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
`connectinfo_stop` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
`acctinputoctets` bigint(20) DEFAULT NULL,
`acctoutputoctets` bigint(20) DEFAULT NULL,
`calledstationid` varchar(50) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`callingstationid` varchar(50) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctterminatecause` varchar(32) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`servicetype` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`framedprotocol` varchar(32) COLLATE utf8_unicode_ci DEFAULT NULL,
`framedipaddress` varchar(15) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`acctstartdelay` int(12) DEFAULT NULL,
`acctstopdelay` int(12) DEFAULT NULL,
`xascendsessionsvrkey` varchar(10) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`radacctid`),
KEY `framedipaddress` (`framedipaddress`),
KEY `acctsessionid` (`acctsessionid`),
KEY `acctsessiontime` (`acctsessiontime`),
KEY `acctuniqueid` (`acctuniqueid`),
KEY `acctstarttime` (`acctstarttime`),
KEY `acctstoptime` (`acctstoptime`),
KEY `nasipaddress` (`nasipaddress`),
KEY `username` (`username`)
) ENGINE=MyISAM AUTO_INCREMENT=3607301 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
CREATE TABLE `userinfo` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`username` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
`firstname` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`lastname` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`email` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`department` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`company` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`workphone` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`homephone` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`mobilephone` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`address` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`city` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`state` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`country` varchar(100) COLLATE utf8_unicode_ci DEFAULT NULL,
`zip` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`notes` varchar(200) COLLATE utf8_unicode_ci DEFAULT NULL,
`changeuserinfo` varchar(128) COLLATE utf8_unicode_ci DEFAULT NULL,
`portalloginpassword` varchar(128) COLLATE utf8_unicode_ci DEFAULT '',
`enableportallogin` int(32) DEFAULT '0',
`creationdate` datetime DEFAULT '0000-00-00 00:00:00',
`creationby` varchar(128) COLLATE utf8_unicode_ci DEFAULT NULL,
`updatedate` datetime DEFAULT '0000-00-00 00:00:00',
`updateby` varchar(128) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `company` (`company`),
KEY `username` (`username`)
) ENGINE=MyISAM AUTO_INCREMENT=191546 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;