php首次连接局域网内的oracle极慢！！

Question

程序用的是yii2
php版本为7.2
连接方式如下：

'class' => 'yii\db\Connection',
//'dsn' => 'oci:dbname=//192.168.0.253:1522/orclshop;charset=utf8',
'dsn' => 'oci:dbname=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.253)(PORT = 1522))(LOAD_BALANCE = yes)(CONNECT_DATA =(SERVER = DEDICATED) (SERVICE_NAME = orclshop)));charset=utf8',
 'username' => 'c##shopdb',
'password' => '123456',

PDO

第一次链接数据库极慢，设置AJAX的超时时间为10秒都不行。。。
有没有大老遇到过此问题？