一个长耗时SQL在TiDB和Mysql上的耗时测试

Posted 2022-07-30 me1onrind

之前看到的TiDB和mysql的性能对比都是大量短耗时请求下的压测，单机情况下TiDB和MySql的确有些差距，不过笔者最近碰到的场景更多是sql要扫描的行数不小的情况下单sql比较耗时的问题，所以自己做了个简单测试这类型sql的耗时。

TiDB单机环境部署

按照官方文档(https://pingcap.com/docs-cn/dev/how-to/get-started/deploy-tidb-from-docker-compose/)直接使用docker-composer部署

git clone https://github.com/pingcap/tidb-docker-compose.git  # 下载

cd tidb-docker-compose && docker-compose pull # 拉取镜像
docker-compose up -d # 启动

命令行客户端连接方式

mysql -h 127.0.0.1 -P 4000 -u root

测试

表结构

create table testTable (
    `id` int(10) unsigned auto_increment primary key,
    `uid` int(10) not null default 0,
    `day` int(6) not null default 0,
    `field1` varchar(16) not null default '',
    `field2` tinyint(3) not null default 0,
    `field3` tinyint(3) not null default 0,
    `field4` tinyint(3) not null default 0,
    `field5` varchar(32) not null default '',
    `field6` varchar(32) not null default '',
    `field7` varchar(32) not null default '',
    key `uid_day_idx` (`uid`,`day`,`field1`, `field3`)
) engine=InnoDB default charset=utf8;

插入数据

• 5000个随机的uid

• day 平均分布在20190801~20190830

• filed1 随机取‘a0‘ ~ ‘a9‘

• field3 随机取0~10

插入数据脚本

<?php
$maxRecordNum = 10000000;

$tableName = 'testTable';
$host = '127.0.0.1';
$port = '4000';
$dbname = 'test';
$username = 'root';
$password = '';
$dsn = "mysql:host=$host;dbname=$dbname;port=$port";

function getDay($maxRecordNum, $i) 
    $item = (int)($maxRecordNum / 30);
    $day = 20190801;
    $add = (int)($i/ $item);
    return $day + $add;


function getRandomFieldOne() 
    static $fieldsOne = [
        "'a0'", "'a1'", "'a2'", "'a3'", "'a4'", "'a5'", "'a6'", "'a7'", "'a8'", "'a9'",
    ];
    return $fieldsOne[rand(0, count($fieldsOne) -1)];


function getRandomFieldTwo() 
    return rand(0, 1);


function getRandomFieldThree() 
    return rand(0, 10);


function getRandomFieldFour() 
    return rand(0, 8);


function generateRecordsValue($day) 
    $minUid = 200000000;
    $maxUid = $minUid + 5000;

    $arrRecord = [
        'uid' => rand($minUid, $maxUid),
        'day' => $day,
        'field1' => getRandomFieldOne(),
        'field2' => getRandomFieldTwo(),
        'field3' => getRandomFieldThree(),
        'field4' => getRandomFieldFour(),
        'field5' => "'static'",
        'field6' => "'static'",
        'field7' => "'static'",
    ];
    return $arrRecord;


try 
    $db = new PDO($dsn, $username, $password);

    $db->query("truncate $tableName;");
    $db->query("alter table $tableName AUTO_INCREMENT=1;");
    $arr = [];
    for ($i = 1; $i <= $maxRecordNum; $i++) 
            $day = getDay($maxRecordNum, $i);
            $arr[] = '(' . implode(',', generateRecordsValue($day)) . ')';
        if ($i % 10000 === 0) 
            $sql = "INSERT INTO $tableName (" . implode(',', array_keys(generateRecordsValue(0))) . ") values" . implode(',', $arr) .';';
            $res = $db->query($sql);
            $arr = [];
            sleep(1);
            echo "$i\n";
        
    
 catch (Exception $e) 
    echo $e->getMessage();

测试sql脚本

查询15天范围内, 2000个uid, 附带两个字段条件

<?php
$tableName = 'testTable';
$host = '127.0.0.1';
$dbname = 'test';
$username = 'root';
$port = '4000';
$password = '';
//$port = '3306';
//$password = 'guapi123';
$dsn = "mysql:host=$host;dbname=$dbname;port=$port";

try 
    $db = new PDO($dsn, $username, $password);
    $arrUid = [];
    $minUid = 200000000;
    for ($i = 0; $i < 2000; $i++) 
        $arrUid[] = $minUid + $i;
    
    $total = 0;
    for ($i = 0; $i < 15; $i++) 
        $startDay = 20190801 + $i;
        $endDay = $startDay + 14;
        $sql = "select field4 from $tableName where uid in (" . implode(',', $arrUid) . ") and day >= $startDay and day<=$endDay and field1 = 'a0' and field3 in (3, 5);";
        $startTime = microtime(true);
        $res = $db->query($sql);
        $endTime = microtime(true);
        $cost = (int)(($endTime - $startTime)  * 1000);
        echo "cost:$costms\n";
        $total += $cost;
    
    echo "avg cost:" . (int)($total / 15) . "ms\n";

 catch (Exception $e) 
    echo $e->getMessage();

测试结果(Mysql和TiDB缓存策略都是默认配置)

TiDB

cost:1744ms
cost:646ms
cost:720ms
cost:614ms
cost:644ms
cost:659ms
cost:662ms
cost:731ms
cost:728ms
cost:669ms
cost:816ms
cost:682ms
cost:778ms
cost:857ms
cost:718ms
avg cost:777ms

Mysql

cost:5256ms
cost:5165ms
cost:5300ms
cost:5461ms
cost:5376ms
cost:5334ms
cost:5435ms
cost:5339ms
cost:5314ms
cost:5278ms
cost:5346ms
cost:5244ms
cost:5387ms
cost:5497ms
cost:5633ms
avg cost:5357ms