diff --git a/var/Typecho/Db.php b/var/Typecho/Db.php
index c33d0c81..1a599e0f 100644
--- a/var/Typecho/Db.php
+++ b/var/Typecho/Db.php
@@ -167,6 +167,16 @@ class Typecho_Db
         return $this->_config;
     }
 
+    /**
+     * 重置连接池
+     * 
+     * @return void
+     */
+    public function flushPool()
+    {
+        $this->_connectedPool = array();
+    }
+
     /**
      * 选择数据库
      * 
diff --git a/var/Upgrade.php b/var/Upgrade.php
index 79614bb0..22f0a6eb 100644
--- a/var/Upgrade.php
+++ b/var/Upgrade.php
@@ -239,6 +239,7 @@ Typecho_Date::setTimezoneOffset($options->timezone);
                     $db->query('DROP TABLE  ' . $prefix . 'users_' . $uuid, Typecho_Db::WRITE);
                     $db->query('CREATE UNIQUE INDEX ' . $prefix . 'users_name ON ' . $prefix . 'users ("name")', Typecho_Db::WRITE);
                     $db->query('CREATE UNIQUE INDEX ' . $prefix . 'users_mail ON ' . $prefix . 'users ("mail")', Typecho_Db::WRITE);
+                    $db->flushPool();
 
                     break;
 
@@ -322,6 +323,7 @@ Typecho_Date::setTimezoneOffset($options->timezone);
                     $db->query('INSERT INTO ' . $prefix . 'metas SELECT * FROM ' . $prefix . 'metas' . $uuid, Typecho_Db::WRITE);
                     $db->query('DROP TABLE  ' . $prefix . 'metas' . $uuid, Typecho_Db::WRITE);
                     $db->query('CREATE INDEX ' . $prefix . 'metas_slug ON ' . $prefix . 'metas ("slug")', Typecho_Db::WRITE);
+                    $db->flushPool();
 
                     break;
 
@@ -773,6 +775,7 @@ Typecho_Date::setTimezoneOffset($options->timezone);
                 $db->query('DROP TABLE  ' . $prefix . 'contents_tmp', Typecho_Db::WRITE);
                 $db->query('CREATE UNIQUE INDEX ' . $prefix . 'contents_slug ON ' . $prefix . 'contents ("slug")', Typecho_Db::WRITE);
                 $db->query('CREATE INDEX ' . $prefix . 'contents_created ON ' . $prefix . 'contents ("created")', Typecho_Db::WRITE);
+                $db->flushPool();
 
                 break;
 
@@ -1154,7 +1157,7 @@ Typecho_Date::setTimezoneOffset($options->timezone);
                 $db->query('INSERT INTO ' . $prefix . 'metas SELECT * FROM ' . $prefix . 'metas' . $uuid, Typecho_Db::WRITE);
                 $db->query('DROP TABLE  ' . $prefix . 'metas' . $uuid, Typecho_Db::WRITE);
                 $db->query('CREATE INDEX ' . $prefix . 'metas_slug ON ' . $prefix . 'metas ("slug")', Typecho_Db::WRITE);
-
+                $db->flushPool();
                 break;
 
             default: