会员数据根据父级id重组为多维数组

<?php
include 'rypconfig.php';
header('Content-Type:text/html; charset=utf8');
set_time_limit(0);
ini_set('memory_limit', '-1');
$order_sql = "SELECT a.user_id,b.price FROM dsc_hyfx_order as a JOIN dsc_hyfx_product as b ON a.product_id=b.product_id WHERE a.is_paid = 1 AND a.is_return=0";
$order_query = mysqli_query($conn,$order_sql);
while ($arr = mysqli_fetch_array($order_query,MYSQLI_ASSOC)){
    $order_data[]=$arr;//订单数据
}

$user_sql = "SELECT user_id,user_name,nick_name,hy_parent_id FROM dsc_users";
$user_query = mysqli_query($conn,$user_sql);
while ($arr = mysqli_fetch_array($user_query,MYSQLI_ASSOC)){
    $arr['price'] = 0;
    $user_data[]=$arr;//用户数据
}


for($i=0;$i<count($order_data);$i++){
    for ($j=0;$j<count($user_data);$j++){
        if($order_data[$i]['user_id']==$user_data[$j]['user_id']){
            $user_data[$j]['price'] += $order_data[$i]['price'];//重组后带消费价格的一维用户数据
        }
    }
}



$tree = getTree($user_data,'0');
function getTree($data,$pId)
{
    $tree = [];
    foreach($data as $k => $v)
    {
        if($v['hy_parent_id'] == $pId)
        { //父亲找到儿子
            $v['children'] = getTree($data, $v['user_id']);
            $tree[] = $v;
        }
    }
    return $tree;
}
var_dump($tree);

数据大概有6W条，到执行关系那里就运行不了了，求大佬教教怎么弄