php 5.4 不使用mysqlnd

由于微博在测试php5.4的相关性能，在5.4开始mysqlnd变成了默认的驱动，

相关说明如下：

 

PHP 5.4 has mysqlnd as default

As of PHP 5.4, the mysqlnd library is a php.net compile time default to all PHP MySQL extensions. Also, the php.net Windows team is using mysqlnd for the official PHP Windows distribution since mysqlnd became available in PHP 5.3.
Advantages of using mysqlnd

The mysqlnd library is highly optimized for and tightly integrated into PHP. The MySQL Client Library cannot offer the same optimizations because it is a general-purpose client library.

The mysqlnd library is using PHP internal C infrastructure for seamless integration into PHP. In addition, it is using PHP memory management, PHP Streams (I/O abstraction) and PHP string handling routines. The use of PHP memory management by mysqlnd allows, for example, memory savings by using read-only variables (copy on write) and makes mysqlnd apply to PHP memory limits. Additional advantages include:

而原有的数据库密码限制导致mysqlnd无法使用，还得使用libmysql驱动,导致php5.4需重新编译，我查看相关configure，将mysqlnd禁用不好使，发现语法判定只要指定mysql支持且不指定相关mysql base设置就会把mysqlnd作为默认驱动 。

下面是该后的相关编译选项：

--with-mysql=/usr \
--with-mysqli=shared,/usr/bin/mysql_config
--with-pdo-mysql=shared,/usr

后重新编译后测试生效