我正在使用mysql开发一个像任何其他社交网站一样的网站。
我希望它能向我的用户提供建议,并且我已在我的应用程序中实现了此功能,但它的工作速度非常慢。此过程需要2-3秒才能从服务器获取结果。它具有所有必要的索引,表上的关系。我已经使用EXPLAIN命令来理解它,但我没有遇到任何问题。 我无法理解它的基本问题是什么。请帮帮我。
这是我的表格结构: 表:UserMaster ~~~~~~~~~~~~~~~~~~
CREATE TABLE `UserMaster` (
`UserID` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
`UserName` varchar(20) DEFAULT NULL,
`EMailID` varchar(50) DEFAULT NULL,
`FirstName` varchar(20) NOT NULL,
`LastName` varchar(20) NOT NULL,
`CityID` mediumint(8) unsigned DEFAULT NULL,
PRIMARY KEY (`UserID`),
UNIQUE KEY `UX_UserMaster_UserName` (`UserName`),
UNIQUE KEY `UX_UserMaster_EMailID` (`EMailID`),
KEY `FK_UserMaster_CityMst_CityID_idx` (`CityID`),
KEY `FK_UserMaster_CountryMst_CountryID_idx` (`CountryID`),
CONSTRAINT `FK_UserMaster_CityMst_CityID`
FOREIGN KEY (`CityID`) REFERENCES `CityMst` (`CityID`) ON DELETE NO ACTION,
CONSTRAINT `FK_UserMaster_CountryMst_CountryID` FOREIGN KEY CountryID REFERENCES CountryMst (CountryID) ON DELETE NO ACTION ON UPDATE CASCADE
)
ENGINE=InnoDB AUTO_INCREMENT=19722 DEFAULT CHARSET=utf8$$
表:UserFriends ~~~~~~~~~~~~~~~~~~~
CREATE TABLE `UserFriends` (
`FriendID` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
`UserID` mediumint(8) unsigned NOT NULL,
`UserID2` mediumint(8) unsigned NOT NULL,
`RequestDate` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
`Status` tinyint(3) unsigned NOT NULL DEFAULT '2',
`ApprovalDate` timestamp NULL DEFAULT NULL,
PRIMARY KEY (`FriendID`),
UNIQUE KEY `UX_UserFriends_UserID_UserID2` (`UserID`,`UserID2`),
KEY `IX_UserFriens_UserID_ApprovalStatus` (`UserID`,`ApprovalStatus`,`UserID2`,`FriendID`,`RequestDate`,`ApprovalDate`),
KEY `FK_UserFriends_UserMaster_UserID_idx` (`UserID`),
KEY `FK_UserFriends_UserMaster_UserID2_idx` (`UserID2`),
CONSTRAINT `FK_UserFriends_UserMaster_UserID` FOREIGN KEY (`UserID`) REFERENCES `UserMaster` (`UserID`) ON DELETE NO ACTION ON UPDATE CASCADE,
CONSTRAINT `FK_UserFriends_UserMaster_UserID2` FOREIGN KEY (`UserID2`) REFERENCES `UserMaster` (`UserID`) ON DELETE NO ACTION ON UPDATE CASCADE
)
ENGINE=InnoDB AUTO_INCREMENT=50825 DEFAULT CHARSET=utf8$$
UserID& UserID2这两个字段都与UserMaster.UserID
链接这是我的选择查询: ~~~~~~~~~~~~~~~~~~~~~~~~~
SELECT
upm.UserID,
upm.UserName,
upm.FirstName,
COALESCE(mf.TotMutualFriends,0) TotMutualFriends
FROM UserMaster upm
LEFT JOIN CityMst ct on ct.CityID = upm.CityID
LEFT JOIN StateMst st on st.StateID = ct.StateID
LEFT JOIN (
SELECT uf.UserID, COUNT(1) TotMutualFriends
FROM (
SELECT uf.UserID, uf.UserID2, uf.ApprovalStatus
FROM UserFriends uf
UNION ALL
SELECT uf.UserID2 UserID, uf.UserID UserID2, uf.ApprovalStatus
FROM UserFriends uf
) uf
INNER JOIN (
SELECT IF(uf.UserID = 1, uf.UserID2, uf.UserID) UserID2
FROM UserFriends uf
WHERE (uf.UserID = 1 OR uf.UserID2 = 1)
AND uf.ApprovalStatus = 1
) uf1 on uf1.UserID2 = uf.UserID2
WHERE uf.ApprovalStatus = 1
GROUP BY uf.UserID
) mf on mf.UserID = upm.UserID
LEFT JOIN (
SELECT DISTINCT usar.UserID2
FROM UserSuggAutoRejct usar
WHERE usar.UserID = 1
UNION
SELECT IF(uf.UserID = 1, uf.UserID2, uf.UserID) UserID2
FROM UserFriends uf
WHERE (uf.UserID = 1 OR uf.UserID2 = 1)
) usar ON usar.UserID2 = upm.UserID
WHERE upm.UserStatus IN(10,11)
AND upm.UserID <> 1
AND upm.UserID NOT IN (1221,2191)
AND usar.UserID2 IS NULL
ORDER BY
(CASE WHEN COALESCE(mf.TotMutualFriends,0) > 0 THEN 0 ELSE 1 END),
(CASE WHEN COALESCE(mf.TotMutualFriends,0) > 0 THEN RAND() ELSE NULL END),
(CASE upm.CityID WHEN 1 THEN 0 ELSE 1 END),
(CASE upm.CityID WHEN 1 THEN RAND() ELSE NULL END),
(CASE ct.StateID WHEN 1 THEN 0 ELSE 1 END),
(CASE ct.StateID WHEN 1 THEN RAND() ELSE NULL END),
(CASE st.CountryID WHEN 91 THEN 0 ELSE 1 END),
(CASE st.CountryID WHEN 91 THEN RAND() ELSE NULL END)
LIMIT 10
这表现得很慢。 evolute需要2-3秒。
答案 0 :(得分:0)
关系数据库可能与社交网站无关。 因为连接表非常慢,请尝试使用其他no-sql数据库(NoSql类型数据库)。 如果你仍然坚持使用mysql,那么尽量不要加入你的查询。
抱歉我的英语不好,如果有的话。