提高复杂sql查询的性能

ajsxfq5m  于 2021-06-19  发布在  Mysql
关注(0)|答案(4)|浏览(460)

几个月以来,我一直在收集公开来源的足球比赛数据。为此,我通过xpath使用php获取特定网站url的数据,该url表示特定足球比赛的数据。然后我做一些数据编辑,使他们适合我需要的方式。下一步也是最后一步是将它们以几个表的形式传输到mysql数据库中。
随着数据库的快速增长,我慢慢地遇到了严重的性能问题。因为我在我的电脑上做所有的事情,而且那台电脑不是一台机器的怪物,所以处理一个匹配已经需要一些时间了。要了解这有多快:在数据挖掘的最初几天,一个匹配大约需要24秒。然而,现在平均值超过了60秒的阈值。
到目前为止,我偶尔会深入研究php代码,并尽可能对其进行改进,因为我认为主要问题在于代码片段不太干净。虽然这有一点帮助,但平均时间在几天后进一步增长,最近我开始意识到一定还有另一个耗时的问题。因此,我编写了一个测试php脚本,在运行主代码时执行某种日志记录。
它显示了我在数据库表中插入数据所做的一些sql查询平均花费了大量时间(我在这里分析了100个匹配项):
首发阵容:6.44秒
长凳替补:8.49秒
再次检查查询,我发现它们非常复杂。
这些表格包括:
TBL启动小组

+----+---------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+------------+------------+--------+  
| id | matchID | player1ID | player2ID | player3ID | player4ID | player5ID | player6ID | player7ID | player8ID | player9ID | player10ID | player11ID | clubID |
+----+---------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+------------+------------+--------+
| 1  |    1    |     1     |     2     |     3     |     4     |     5     |     6     |     7     |     8     |     9     |     10     |     11     |   1    |
| 2  |    1    |    12     |    13     |    14     |    15     |    16     |    17     |    16     |    17     |    18     |     19     |     20     |   2    |
| 3  |    2    |     1     |     2     |     3     |     4     |     5     |     6     |     7     |     8     |     9     |     10     |     11     |   1    |
| 4  |    2    |    21     |    22     |    23     |    24     |    25     |    26     |    27     |    28     |    29     |     30     |     31     |   3    |
+----+---------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+-----------+------------+------------+--------+

TBL替代品

+----+---------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+--------+  
| id | matchID | player12ID | player13ID | player14ID | player15ID | player16ID | player17ID | player18ID | player19ID | player20ID | player21ID | player22ID | player23ID | clubID |
+----+---------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+--------+
| 1  |    1    |     32     |     33     |     34     |     35     |     36     |     37     |     38     |     39     |     40     |     41     |     42     |     43     |   1    |
| 2  |    1    |     44     |     45     |     46     |     47     |     48     |     49     |     50     |     51     |     52     |     53     |     54     |     55     |   2    |
| 3  |    2    |     32     |     33     |     34     |     35     |     36     |     37     |     38     |     39     |     40     |     41     |     42     |     43     |   1    |
| 4  |    2    |     56     |     57     |     58     |     59     |     60     |     61     |     61     |     62     |     63     |     64     |     65     |     66     |   3    |
+----+---------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+------------+--------+

TBL匹配

+---------+---------------------+-------------+------------------+
| matchID |         date        |    coach1   |      coach2      |
+---------+---------------------+-------------+------------------+
|    1    | 2006-08-19 22:00:00 | Piotr Nowak | Fernando Clavijo |
|    2    | 2006-08-15 21:00:00 | Piotr Nowak |   Mustafa Ugur   |
+---------+---------------------+-------------+------------------+

tblplayer公司

+----------+------------------------+------------------+
| playerID |       namePlayer       |      short       |
+----------+------------------------+------------------+
|     1    |       Enis Ulusan      |    enis-ulusan   |
|     2    |   Grant Robert Murray  |   grant-murray   |
|     3    |     Evgeniy Shpedt     |  evgeniy-shpedt  |
|     4    | Mihai Alexandru Costea |   mihai-costea   |
|     5    |       Jan Zolna        |     jan-zolna    |
|     6    |    Adrian Gheorghiu    | adrian-gheorghiu |
|     7    | Marius Marian Croitoru | marius-croitoru  |
|     8    |    Jacov Nachtailer    | jacov-nachtailer |
|    ...   |          ...           |        ...       |
+----------+------------------------+------------------+

TBL俱乐部

+--------+-----------------+
| clubID |    nameClub     |
+--------+-----------------+
|    1   |   D.C. United   |
|    2   | Colorado Rapids |
|    3   | Caykur Rizespor |
+--------+-----------------+

这些是所涉及的问题:
sql查询启动组

$tblstarting_squad = 'INSERT INTO tblStartingSquad (matchID, player1ID, player2ID, player3ID, player4ID, player5ID, player6ID, player7ID, player8ID, player9ID, player10ID, player11ID, clubID) 
                    SELECT
                        (SELECT matchID FROM tblMatch WHERE date = "' . $match_date . '" AND coach1 = "' . $match_coach_home . '" AND coach2 = "' . $match_coach_away . '"), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[0] . '" AND short = "' . $player_short[0] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[1] . '" AND short = "' . $player_short[1] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[2] . '" AND short = "' . $player_short[2] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[3] . '" AND short = "' . $player_short[3] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[4] . '" AND short = "' . $player_short[4] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[5] . '" AND short = "' . $player_short[5] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[6] . '" AND short = "' . $player_short[6] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[7] . '" AND short = "' . $player_short[7] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[8] . '" AND short = "' . $player_short[8] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[9] . '" AND short = "' . $player_short[9] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[10] . '" AND short = "' . $player_short[10] . '" LIMIT 1), 
                        (SELECT clubID FROM tblClub WHERE nameClub = "' . $match_club[1] . '" LIMIT 1)
                    WHERE NOT EXISTS (
                        SELECT e.matchID 
                        FROM tblStartingSquad As e
                        INNER JOIN tblMatch As m
                            ON e.matchID = m.matchID
                        WHERE m.date = "' . $match_date . '" AND m.coach1 = "' . $match_coach_home . '" AND m.coach2 = "' . $match_coach_away . '" AND e.clubID = (SELECT clubID FROM tblClub WHERE nameClub = "' . $match_club[1] . '")
                    );';

if (!mysqli_query($db_connection, $tblstarting_squad)) {
                    echo("Error description $tblstarting_squad: " . mysqli_error($db_connection) . "<br />");
                }

sql查询工作台

$tblsubstitutes = 'INSERT INTO tblSubstitutes (matchID, player12ID, player13ID, player14ID, player15ID, player16ID, player17ID, player18ID, player19ID, player20ID, player21ID, player22ID, player23ID, clubID) 
                    SELECT
                        (SELECT matchID FROM tblMatch WHERE date = "' . $match_date . '" AND coach1 = "' . $match_coach_home . '" AND coach2 = "' . $match_coach_away . '"), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[11] . '" AND short = "' . $player_short[11] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[12] . '" AND short = "' . $player_short[12] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[13] . '" AND short = "' . $player_short[13] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[14] . '" AND short = "' . $player_short[14] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[15] . '" AND short = "' . $player_short[15] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[16] . '" AND short = "' . $player_short[16] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[17] . '" AND short = "' . $player_short[17] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[18] . '" AND short = "' . $player_short[18] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[19] . '" AND short = "' . $player_short[19] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[20] . '" AND short = "' . $player_short[20] . '" LIMIT 1), 
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[21] . '" AND short = "' . $player_short[21] . '" LIMIT 1),
                        (SELECT playerID FROM tblPlayer WHERE namePlayer = "' . $player_name[22] . '" AND short = "' . $player_short[22] . '" LIMIT 1), 
                        (SELECT clubID FROM tblClub WHERE nameClub = "' . $match_club[1] . '" LIMIT 1)
                    WHERE NOT EXISTS (
                        SELECT e.matchID 
                        FROM tblSubstitutes As e
                        INNER JOIN tblMatch As m
                            ON e.matchID = m.matchID
                        WHERE m.date = "' . $match_date . '" AND m.coach1 = "' . $match_coach_home . '" AND m.coach2 = "' . $match_coach_away . '" AND e.clubID = (SELECT clubID FROM tblClub WHERE nameClub = "' . $match_club[1] . '")
                    );';

if (!mysqli_query($db_connection, $tblsubstitutes)) {
                    echo("Error description $tblsubstitutes: " . mysqli_error($db_connection) . "<br />");
                }

两个查询实际上是相同的。他们插入 playerID 11名(分别为12名)选手进入 tblStartingSquad (分别为 tblSubstitutes )如果没有其他条目具有相同的数据。这个 playerID 必须事先在数据库中进行检查,因为原始数据没有单独的id namePlayer 以及 short 从table上 tblPlayer .
table tblStartingSquad 以及 tblSubstitutes 本身当前包含110000行(55000个匹配项), tblPlayer 在100000排。
我在谷歌上搜索了一些解决方案,但没有找到任何能提高整体速度的方法。我所理解的问题是,我必须逐个检查每个玩家,所以我得到11和12个子查询。这不是很优雅,但我真的不知道如何改进。也许stackoverflow的人有什么建议?

8tntrjer

8tntrjer1#

这些说法并不复杂。它们只是包含大量的查找。所以一定要快速查找。您需要以下索引。如果还没有,请将它们添加到数据库中。

create index idx_find_player on tblplayer (nameplayer, short, playerid);
create index idx_find_club on tblclub (nameclub, clubid)
create index idx_find_match on tblmatch (date, coach1, coach2, matchid)

create index idx_find_squad1 on tblstartingsquad (matchid, clubid)
create index idx_find_squad2 on tblSsartingsquad (clubid, matchid)

create index idx_find_subs1 on tblsubstitutes (matchid, clubid)
create index idx_find_subs2 on tblsubstitutes (clubid, matchid)

我不确定哪个队伍索引更可能被使用,所以创建两个,看看dbms选择哪个。然后你可以放下另一个。替代指标也一样。

fxnxkyjh

fxnxkyjh2#

重新考虑你的宽table设计为长table设计。带数字后缀的列永远不是理想的数据存储。划船很便宜。柱子很贵。在长格式中,联接、聚合、搜索、索引等都要容易得多。否则,您的查询将很复杂,如您所示,有12个子查询甚至自联接!
有趣的是,您的tblclub和tblplayer是长格式的,但不是tblstartingsquad和tblsubstitutes!只需将所有无关的player列移到一个行中,其中的行表示不同的player:
TBL启动小组

ID   MatchID   PlayerID    ClubID  
  1         1          5         1
  2         1          8         1
  3         1          9         1
...

TBL替代品

ID   MatchID   PlayerID    ClubID
  1         1          2         1
  2         1         16         1
  3         1          7         1
...

tblmatch(为了清晰起见,重命名了coach列)

ID                    Date      HomeCoach          AwayCoach
 1     2006-08-19 22:00:00    Piotr Nowak   Fernando Clavijo
 2     2006-08-15 21:00:00    Piotr Nowak       Mustafa Ugur

PHP
从这个数据库设计中,您可以运行一个更简单的php参数化查询调用,使用pdo甚至更简单,而不是 mysqli 用于绑定数组中的许多参数。

// OPEN CONNECTION
$dbconn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// SET PDO ERROR MODE TO EXCEPTION
$dbconn -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// PREPARED STATEMENT
$sql = "INSERT INTO tblStartingSquad (`Match`, `PlayerID`, `ClubID`)
        SELECT m.MatchID, p1.PlayerID, c.ClubID
        FROM 
           (SELECT p.PlayerID
            FROM tblPlayer p
            WHERE p.namePlayer IN (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
           ) p1
        INNER JOIN 
           (SELECT p.PlayerID
            FROM tblPlayer p
            WHERE p.short IN (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
           ) p2 ON p1.PlayerID = p2.PlayerID
        CROSS JOIN
            (SELECT MatchID 
             FROM tblMatch
             WHERE `date` = ? AND HomeCoach = ? AND AwayCoach = ?) m
        CROSS JOIN
            (SELECT ClubID 
             FROM tblClub
             WHERE nameClub = ?) c
        WHERE NOT EXISTS
             (SELECT 1 FROM tblStartingSquad As e
              WHERE e.MatchID = m.matchID)"

try {
     // INITIALIZE STATEMENT
     $stmt = $dbconn->prepare($sql);

     $params = array($player_name[0], $player_name[1], $player_name[2], 
                     $player_name[3], $player_name[4], $player_name[5], 
                     $player_name[6], $player_name[7], $player_name[8], 
                     $player_name[9], $player_name[10],  
                     $player_short[0], $player_short[1], $player_short[2],
                     $player_short[3], $player_short[4], $player_short[5], 
                     $player_short[6], $player_short[7], $player_short[8], 
                     $player_short[9], $player_short[10],         
                     $match_date, $match_coach_home, $match_coach_away, $match_club);

     // ITERATIVELY BIND PARAMS
     foreach($params as $key => $val) {
        $stmt->bindParam($key+1, $val, PDO::PARAM_STR);
     }

     // EXECUTE ACTION
     $stmt->execute();

} catch (PDOException $e) {
     echo "Error: " . $e->getMessage();
}

对tblsubstitutes执行类似的调用,调整append查询的目的地和 WHERE 子句和参数值。

lx0bsm1f

lx0bsm1f3#

正如o.jones在评论中已经指出的那样,为了判断性能问题,查看更多(php)代码会很有帮助。尽管重新设计了数据库,但另一个快速建议实际上是运行一个循环,并为playerids的各个查询使用一个准备好的语句。这可能会给你一个轻微的性能提升。
在我看来,用php做更多的工作,而不是将数据获取的逻辑外包给sql,这在逻辑上是合理的。

628mspwn

628mspwn4#

为了得到准确的答案,我们必须在sql中查看您的执行计划,请发送到这里,这样我就可以帮助您解决问题
在此之前,我认为您做的都是错误的,您可以在数据库中定义用户定义的表并传递值,而不是为单行编写一个select。通过这样做,您可以在sql和服务器端代码中获得更好的性能,我向您保证,您在第一个级别上获得了最好的性能,在这之后,正如我之前所说,您需要执行计划
声明您的类型(不要忘记用自己的数据类型更改数据类型)
创建类型[dbo].[com\u listofguid]作为表(nameplayer nvarchar(256)not null,short nvarchar(256)not null)
不要在代码中创建select语句,只需声明一个datatable并向其中填充数据,然后像传递其他参数一样传递它(不要忘记设置一个与用户定义的表类型完全相同的列名称)3.在sql代码中,只需将用户定义的表类型与表连接起来,然后将它们插入到目标表中(我给您一个例如,你需要改变)
创建过程procedure\u your\u name@objecttable type\u your\u name readonly as insert into target\u table()从第一个\u表f inner join@objecttable t中选择*在f.nameplayer=t.nameplayer和t.short=f.short上

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