Wie sollte ich die Datenspeicherung auswählen, wenn ich eine Website mit einer sehr kleinen Anzahl von Benutzern erstellen möchte?

<code><?php

function db() {
    static $db;
    if ($db) {
        return $db;
    } else {
        try {
            $db = new PDO('sqlite:'.$_SERVER['DOCUMENT_ROOT'].'/../data.db3');
        } catch (PDOException $e) {
            echo $e->getMessage();
            exit();
        }
        return $db;
    }
}

function insert($title = '', $content = '') {
    global $app;
    $db = db();
    $stmt = $db->prepare('INSERT INTO posts (post_title, post_content) VALUES (?, ?)');
    $stmt->bindParam(1, $title,   PDO::PARAM_STR);
    $stmt->bindParam(2, $content, PDO::PARAM_STR);
    $stmt->execute();
    return ($stmt->rowCount() !== 0) ? 
        array(true,  'lastInsertId' => $db->lastInsertId()) : 
        array(false, 'lastInsertId' => $db->lastInsertId());
}

function select($id = '') {
    global $app;
    $db = db();
    if (!empty($id)) {
        return $db->query('SELECT * FROM posts WHERE id = '.intval($id))->fetchAll(PDO::FETCH_ASSOC);
    } else {
        return $db->query('SELECT * FROM posts')->fetchAll(PDO::FETCH_ASSOC);
    }
}

function select_v2($id = '') {
    global $app;
    $db = db();
    if (!empty($id)) {
        $stmt = $db->prepare('SELECT * FROM posts WHERE id = ?');
        $stmt->bindParam(1, $id, PDO::PARAM_INT);
    } else {
        $stmt = $db->prepare('SELECT * FROM posts');
    }
    $stmt->execute();
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

function update($id, $title = '', $content = '') {
    global $app;
    $db = db();
    
    //echo PDO::ATTR_AUTOCOMMIT; //返回0可见PDO默认禁用自动提交事务.
    //echo $db->getAttribute(PDO::ATTR_AUTOCOMMIT); exit(); //返回1可见MySQL默认会自动提交事务.
    
    //SQLite不支持设置PDO::ATTR_AUTOCOMMIT:
    //SQLite: Uncaught exception 'PDOException' with message 'The auto-commit mode cannot be changed for this driver'
    //$db->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
    $db->beginTransaction();
    $stmt = $db->prepare('UPDATE posts SET post_title = ?, post_content = ? WHERE id = ?');
    
    $stmt->execute(array($title,$content,$id)); //所有值视作PDO::PARAM_STR处理
    //$stmt->execute(array(':title' => $title,':content' => $content,':id' => $id));
    //$stmt->bind_param('ssi', $title, $content, $id); //对比mysqli
    
    echo 'sleep(3);'."\n";
    sleep(3);
    
    $db->commit();
    //$db->setAttribute(PDO::ATTR_AUTOCOMMIT, true); //commit提交事务后autocommit记得重新设为true
    return ($stmt->rowCount() !== 0) ? true : false;
}

function delete($id) {
    global $app;
    $db = db();
    return ($db->query('DELETE FROM posts WHERE id = '.intval($id))->rowCount() !== 0) ? true : false;
}

function delete_v2($id) {
    global $app;
    $db = db();
    $stmt = $db->prepare('DELETE FROM posts WHERE id = ?');
    $stmt->bindParam(1, $id, PDO::PARAM_INT);
    $stmt->execute();
    return ($stmt->rowCount() !== 0) ? true : false;
}

header('Content-Type: text/plain; charset=utf-8');

$sqlite = "CREATE TABLE IF NOT EXISTS posts (
    id           INTEGER PRIMARY KEY,
    post_title   VARCHAR(255) NOT NULL,
    post_content TEXT         NOT NULL
)";

db()->query('DROP TABLE IF EXISTS posts;') or exit();
db()->query($sqlite) or exit();

//并发时,SQLite在insert时因为库文件被其他请求锁住而导致阻塞
echo "var_export(insert('标题1', '内容1'));\n";
var_export(insert('标题1', '内容1'));
echo "\n\n";

echo "var_export(insert('标题2', '内容2'));\n";
var_export(insert('标题2', '内容2'));
echo "\n\n";

echo "var_export(select());\n";
var_export(select());
echo "\n\n";

echo "var_export(update(2, '标题2_更新','内容2_更新'));\n";
var_export(update(2, '标题2_更新','内容2_更新'));
echo "\n\n";

echo "var_export(select(2));\n";
var_export(select(2));
echo "\n\n";

echo "var_export(delete(2));\n";
var_export(delete(2));
echo "\n\n";

echo "var_export(select());\n";
var_export(select());
echo "\n\n";</code>

<code><?php
header('Content-Type: text/plain; charset=utf-8');
$file = __DIR__.'/data.php'; //数据文件,别人直接URL访问也下载不了
if(!file_exists($file)) {
    file_put_contents($file, '<?php return array();'); //file_put_contents($file, '');
}
$fp = fopen($file, 'r+'); //读写方式打开,将文件指针指向文件头
if(flock($fp, LOCK_EX)) { //阻塞到获取排它锁
    //锁定数据文件后再进行读写
    $arr = require $file; //$arr = unserialize(file_get_contents($file));
    $arr[] = date('Y-m-d H:i:s');
    ftruncate($fp, 0); //清空文件
    fwrite($fp, '<?php return '.var_export($arr, true).';'); //fwrite($fp, serialize($arr));
    fflush($fp); //在释放锁之前刷新输出
    //sleep(10); //睡眠10秒,在此期间其他工作进程的请求将被阻塞
    flock($fp, LOCK_UN); //释放锁定
    echo file_get_contents($file)."\n";
}
fclose($fp);</code>