Question

我正在使用phpMyAdmin 4.2.7.1。 MySQL 5.6.16。 MS Windows Server 2012 R2 Standard，4GB RAM，Intel Xeon E5-2620 @ 2.00GHz。几天前我遇到过MySQL查询中遇到问题的问题。在过去的平均查询中，返回结果的速度会快5分钟，现在即使在几个小时之后也无法返回结果。这是我创建的视图：

CREATE ALGORITHM=UNDEFINED DEFINER=root@localhost SQL SECURITY DEFINER 
VIEW okp_view AS 
     select q.MessageId AS MessageId,
q.SenderTimeStamp AS SenderTimeStamp,
r.GsbId AS GsbId,
r.ReceiverTimeStamp AS ReceiverTimeStamp,
r.FinalTimeStamp AS FinalTimeStamp,
k.ErrorCode AS ErrorCodeRes,
t.ErrorType AS ErrorTypeRes,
g.ID AS ID,
g.OIB AS OIB,
g.MssgText AS MssgText,
s.ErrorCode AS ErrorCodeResMssg,
m.ErrorType AS ErrorTypeMssg 
     from ((((((soap_req_env q 
join soap_res_env r) 
join soap_res_err k) 
join res_err_type t) 
join soap_message g) 
join soap_mssg_err s) 
join mssg_err_type m) 
     where ((q.MessageId = g.MessageId) 
and (g.ID = s.ID) 
and (s.ErrorCode = m.ErrorCode) 
and (q.MessageId = r.MessageId) 
and (r.GsbId = k.GsbId) 
and (k.ErrorCode = t.ErrorCode)) 
order by q.SenderTimeStamp desc;

视图包含超过500000条记录。这些是MySQL表的索引：

TABLE_NAME,INDEX_NAME
mssg_err_type,ErrorCode
registar_e_poruka_za_okp,PRIMARY
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_posiljatelja_e_poruka1_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_zivotnih_situacija1_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_tema1_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_razine_pouzdanosti_vje_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_tipa_privitka1_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_frekvencije_slanja_por_idx
registar_e_poruka_za_okp,fk_Registar_e_poruka_za_OKP_Sifarnik_statusa_e_poruke1_idx
res_err_type,ErrorCode
soap_message,PRIMARY
soap_message,MessageId
soap_mssg_err,ID
soap_mssg_err,ErrorCode
soap_req_env,PRIMARY
soap_res_env,PRIMARY
soap_res_env,MessageId
soap_res_err,GsbId
soap_res_err,ErrorCode

现在，MySQL为我提供了此查询的数据：

SELECT * FROM okp_view WHERE SenderTimeStamp>="2015-05-25" 
Showing rows 0 - 24 (2132 total, Query took 13.9374 seconds.)

如果我尝试使用以下方法检索更大的子集：

SELECT * FROM okp_view WHERE SenderTimeStamp>="2015-05-24"

但需要很长时间。

如何改进数据库架构以优化数据库并加速数据检索。

编辑：如果我在没有视图的情况下使用查询，则需要很长时间：

select * from soap_req_env q, soap_res_env r, soap_res_err k, res_err_type t, soap_message g, soap_mssg_err s, mssg_err_type m
where q.messageid=g.messageid
and g.id=s.id
and s.errorcode=m.errorcode
and q.messageid=r.messageid
and r.gsbid=k.gsbid
and k.errorcode=t.errorcode
and q.sendertimestamp>="2015-05-15"
ORDER BY `q`.`SenderTimeStamp` DESC

SHOW VARIABLES LIKE '%buffer%';的结果是

Variable_name   Value
bulk_insert_buffer_size     8388608
innodb_buffer_pool_dump_at_shutdown     OFF
innodb_buffer_pool_dump_now     OFF
innodb_buffer_pool_filename     ib_buffer_pool
innodb_buffer_pool_instances    8
innodb_buffer_pool_load_abort   OFF
innodb_buffer_pool_load_at_startup  OFF
innodb_buffer_pool_load_now     OFF
innodb_buffer_pool_size     16777216
innodb_change_buffer_max_size   25
innodb_change_buffering     all
innodb_log_buffer_size  8388608
innodb_sort_buffer_size     1048576
join_buffer_size    262144
key_buffer_size     16777216
myisam_sort_buffer_size     8388608
net_buffer_length   8192
preload_buffer_size     32768
read_buffer_size    262144
read_rnd_buffer_size    524288
sort_buffer_size    524288
sql_buffer_result   OFF

我的表结构是：

CREATE TABLE `soap_req_env` (
 `MessageId` char(36) COLLATE utf8_croatian_ci NOT NULL,
 `SenderTimeStamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 PRIMARY KEY (`MessageId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

    CREATE TABLE `soap_res_env` (
 `MessageId` char(36) COLLATE utf8_croatian_ci NOT NULL,
 `GsbId` char(36) COLLATE utf8_croatian_ci NOT NULL DEFAULT '',
 `ReceiverTimeStamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 `FinalTimeStamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 PRIMARY KEY (`GsbId`),
 KEY `MessageId` (`MessageId`),
 CONSTRAINT `soap_res_env_ibfk_1` FOREIGN KEY (`MessageId`) REFERENCES `soap_req_env` (`MessageId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

CREATE TABLE `soap_res_err` (
 `GsbId` char(36) COLLATE utf8_croatian_ci NOT NULL,
 `ErrorCode` char(4) COLLATE utf8_croatian_ci NOT NULL,
 UNIQUE KEY `GsbId` (`GsbId`,`ErrorCode`),
 KEY `ErrorCode` (`ErrorCode`),
 CONSTRAINT `soap_res_err_ibfk_2` FOREIGN KEY (`ErrorCode`) REFERENCES `res_err_type` (`ErrorCode`),
 CONSTRAINT `soap_res_err_ibfk_3` FOREIGN KEY (`GsbId`) REFERENCES `soap_res_env` (`GsbId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

 CREATE TABLE `res_err_type` (
 `ErrorCode` char(4) COLLATE utf8_croatian_ci NOT NULL,
 `ErrorType` text COLLATE utf8_croatian_ci NOT NULL,
 UNIQUE KEY `ErrorCode` (`ErrorCode`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

CREATE TABLE `soap_message` (
 `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
 `MessageId` char(36) COLLATE utf8_croatian_ci NOT NULL,
 `OIB` char(11) COLLATE utf8_croatian_ci NOT NULL,
 `MssgText` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
 PRIMARY KEY (`ID`),
 UNIQUE KEY `MessageId` (`MessageId`,`OIB`),
 CONSTRAINT `soap_message_ibfk_1` FOREIGN KEY (`MessageId`) REFERENCES `soap_req_env` (`MessageId`)
) ENGINE=InnoDB AUTO_INCREMENT=571197 DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

CREATE TABLE `soap_mssg_err` (
 `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
 `ErrorCode` char(4) COLLATE utf8_croatian_ci NOT NULL,
 KEY `ID` (`ID`),
 KEY `ErrorCode` (`ErrorCode`),
 CONSTRAINT `soap_mssg_err_ibfk_2` FOREIGN KEY (`ErrorCode`) REFERENCES `mssg_err_type` (`ErrorCode`),
 CONSTRAINT `soap_mssg_err_ibfk_3` FOREIGN KEY (`ID`) REFERENCES `soap_message` (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=571197 DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

CREATE TABLE `mssg_err_type` (
 `ErrorCode` char(4) COLLATE utf8_croatian_ci NOT NULL,
 `ErrorType` text COLLATE utf8_croatian_ci NOT NULL,
 UNIQUE KEY `ErrorCode` (`ErrorCode`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_croatian_ci

Answer 1

UUID的邪恶

（我在这里走出困境，不确定是否涉及UUID。）

MessageId CHAR（36）COLLATE utf8 ... PRIMARY KEY

闻起来像是一个“UUID”的十六进制字符串;我假设它是。

问题＃1

CHAR(36) CHARACTER SET utf8在任何地方消耗108个字节。它似乎是多个表中的一个键，并且可能显示在辅助表中（InnoDB在每个二级密钥中隐含地包含PRIMARY KEY。）对于500K记录，这可以累加许多兆字节，可能是千兆字节。

修复＃1：

CHAR(36) CHARACTER SET ascii只有36个字节。

修复＃2：

将其转换为二进制并将其存储在BINARY(16)中，这只需要16个字节。我的UUID blog提供了转化代码。

问题＃2

UUID非常随机。一旦UUID索引大于innodb_buffer_pool_size（或key_buffer_size，如果是MyISAM）中的缓存，越来越多的查找必须到达磁盘。例如，当索引是缓存的20倍时，95％（或更多）的查找需要磁盘命中。

在500000条记录之后，MySQL变得极其缓慢

1 个答案: