做一个导入csv数据的网页，有几十上百万条数据应该用什么方案或考虑哪些问题？

<?php
//开启事务,批量插入
$db = new mysqli('127.0.0.1','user','pass','dbname',3306);
$db->query('SET AUTOCOMMIT=0');
$db->query('START TRANSACTION');

//导入CSV表格:CSV转数组
$fp = fopen('file.csv', 'r');
while ( ($row = fgetcsv($fp)) !== FALSE ) {
    //从文件指针中读入一行并解析CSV
    $stmt = $db->prepare('INSERT INTO posts (id, post_title, post_content) VALUES (?,?,?)');
    $stmt->bind_param('iss', $row[0], $row[1], $row[2]); //这里假设每行内容分别为ID,标题和内容
    $stmt->execute();
    //如果插入失败,改为更新
    if($stmt->affected_rows == 0) {
        $stmt = $db->prepare('UPDATE posts SET post_title = ?, post_content = ? WHERE id = ?');
        $stmt->bind_param('ssi', $row[1], $row[2], $row[0]);
        $stmt->execute();
        if($stmt->affected_rows == 0) {
            echo 'Import '.$row[0].' failed!'."\n";
        }
    }
}
fclose($fp);

//提交事务
$db->query('COMMIT'); //失败的操作已经echo输出来了,不需要回滚ROLLBACK
$db->query('SET AUTOCOMMIT=1');