1、$uses和loadModel的使用
在CakePHP1.3.x版本中尽量不使用$uses, 因为这会全部加载使用到的model，占用内存和消耗不必要的时间。
相反在需要使用model的地方，使用loadModel加载它。在不需要关联数据的情况下，设置其recursive属性为-1。
另外控制器默认的数据模型不用加载，如果users_controller不用调用loadModel('User')，User模型及其关联模型会自动加载，
在控制器中只要直接使用即可：
$this->User... ;
$this->User->Role...
使用lazy loading技术, 1.3版本有一个lazy_model，把你的app_model的基类换成LazyModel，
将使得model仅在实际调用的地方才会真正加载。
2、eval和requestAction的使用
尽量不要使用eval和requestAction。eval会导致新的脚本解析进程，而requestAction等同于发出一个新的请求。
eval可以用{}或$$类似语法替换，如
case 1
$this->{$this->modelClass}->hasField("country_id");
-----------------------------------------------------------------
case 2
$foo = 'city';
$$foo = 'shanghai';
requestAction用view/helper替换
3、Cache
需要分布式数据共享的地方用memcached，本地数据尽量用Apc。在使用到Cache::write/read的地方通过参数指定使用core.php中配置的哪个Cache。
4. do not use config::load, instead use include_once() as long as you know the file name and must be therethe file_exist() check takes much time.
5. never put loadModel or ClassRegistry::init in a loop, these functions take much time
6. when request deals/*, it also loaded all associated models even you have set $this->Deal->recursive to -1; remember this, if you in all cases didn't need to retrieve associated tables' data, just remove association from the model.
7. when request deals/*, it also setup all routes for all plugins, admin/*, so you need to cut down your plugins as less as possible.
8. optimize static mapping codes:Router::mapResources('deals');Router::mapResources('vendors');Router::mapResources('users');to dynamically mapping if(isset($uri_first) && $uri_first != 'admin') { Router::mapResources(strtolower($uri_first)); } 6. load components on the fly rather than put it in $components
7. load model on the fly rather than put it in $used
8. cake loaded all common libs at cake/libs directory even it is not used in configure.php->App::import->App::_find,
so a better way is to overwrite the pre-loading to lazy loading.
