修改缓存状态，

mysql 默认打开
pg默认关闭

@@ -36,7 +36,7 @@ class Root
      * 缓存
      * @var bool
      */
-    protected $_cacheStatus = false;
+    protected $_cacheStatus = true;
 
     /**
      * 缓存key

@@ -22,6 +22,13 @@ use Hood\Cache as hoodCache;
  */
 class PDOConnection extends Root
 {
+
+    /**
+     * 关闭缓存
+     * @var bool
+     */
+    protected $_cacheStatus = false;
+
     /**
      * 数据库连接池
      * @var array